simh-testsetgenerator/HP2100/hp2100_cpu0.c
2020-02-16 22:25:15 -08:00

801 lines
37 KiB
C

/* hp2100_cpu0.c: HP 2100/1000 UIG dispatcher, user microcode, and unimplemented instruction stubs
Copyright (c) 2006-2018, J. David Bryan
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
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The above copyright notice and this permission notice shall be included in
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CPU0 UIG dispatcher, user microcode, and unimplemented firmware options
02-Aug-18 JDB Moved UIG dispatcher from hp2100_cpu1.c
25-Jul-18 JDB Use cpu_configuration instead of cpu_unit.flags for tests
01-Aug-17 JDB Changed .FLUN and self-tests to test for unimplemented stops
09-May-12 JDB Separated assignments from conditional expressions
04-Nov-10 JDB Removed DS note regarding PIF card (is now implemented)
18-Sep-08 JDB .FLUN and self-tests for VIS and SIGNAL are NOP if not present
11-Sep-08 JDB Moved microcode function prototypes to hp2100_cpu1.h
05-Sep-08 JDB Removed option-present tests (now in UIG dispatchers)
Added "user microcode" dispatcher for unclaimed instructions
26-Feb-08 HV Removed and implemented "cpu_vis" and "cpu_signal"
22-Nov-07 JDB Removed and implemented "cpu_rte_ema"
12-Nov-07 JDB Removed and implemented "cpu_rte_vma" and "cpu_rte_os"
01-Dec-06 JDB Removed and implemented "cpu_sis".
26-Sep-06 JDB Created
Primary references:
- HP 1000 M/E/F-Series Computers Technical Reference Handbook
(5955-0282, March 1980)
- HP 1000 M/E/F-Series Computers Engineering and Reference Documentation
(92851-90001, March 1981)
- Macro/1000 Reference Manual
(92059-90001, December 1992)
Additional references are listed with the associated firmware
implementations, as are the HP option model numbers pertaining to the
applicable CPUs.
This module contains the User Instruction Group (a.k.a. "Macro") dispatcher
for the 2100 and 1000 (21MX) CPUs. The UIG simulators reside in separate
modules, due to the large number of firmware options available for these
machines. Unit flags indicate which options are present in the current
system.
It also contains a user-microprogram dispatcher to allow simulation of
site-specific firmware. All UIG instructions unclaimed by installed firmware
options are directed here and may be simulated by writing the appropriate
code.
The module also contains template simulations for the firmware options that
have not yet been implemented. When a given firmware option is implemented,
it should be moved out of this file and into another (or its own, depending
on complexity).
Finally, this module provides generalized instruction operand processing.
The 2100 and 1000 machines were microprogrammable; the 2116/15/14 machines
were not. Both user- and HP-written microprograms were supported. The
microcode address space of the 2100 encompassed four modules of 256 words
each. The 1000 M-series expanded that to sixteen modules, and the 1000
E/F-series expanded that still further to sixty-four modules. Each CPU had
its own microinstruction set, although the micromachines of the various 1000
models were similar internally.
The UIG instructions were divided into ranges assigned to HP firmware
options, reserved for future HP use, and reserved for user microprograms.
User microprograms could occupy any range not already used on a given
machine, but in practice, some effort was made to avoid the HP-reserved
ranges.
User microprogram simulation is supported by routing any UIG instruction not
allocated to an installed firmware option to a user-firmware dispatcher.
Site-specific microprograms may be simulated there. In the absence of such a
simulation, an unimplemented instruction stop will occur.
Regarding option instruction sets, there was some commonality across CPU
types. EAU instructions were identical across all models, and the floating
point set was the same on the 2100 and 1000. Other options implemented
proper instruction supersets (e.g., the Fast FORTRAN Processor from 2100 to
1000-M to 1000-E to 1000-F) or functional equivalence with differing code
points (the 2000 I/O Processor from 2100 to 1000, and the extended-precision
floating-point instructions from 1000-E to 1000-F).
The 2100 decoded the EAU and UIG sets separately in hardware and supported
only the UIG 0 code points. Bits 7-4 of a UIG instruction decoded one of
sixteen entry points in the lowest-numbered module after module 0. Those
entry points could be used directly (as for the floating-point instructions),
or additional decoding based on bits 3-0 could be implemented.
The 1000 generalized the instruction decoding to a series of microcoded
jumps, based on the bits in the instruction. Bits 15-8 indicated the group
of the current instruction: EAU (200, 201, 202, 210, and 211), UIG 0 (212),
or UIG 1 (203 and 213). UIG 0, UIG 1, and some EAU instructions were decoded
further by selecting one of sixteen modules within the group via bits 7-4.
Finally, each UIG module decoded up to sixteen instruction entry points via
bits 3-0. Jump tables for all firmware options were contained in the base
set, so modules needed only to be concerned with decoding their individual
entry points within the module.
While the 2100 and 1000 hardware decoded these instruction sets differently,
the decoding mechanism of the simulation follows that of the 1000 E/F-series.
Where needed, CPU type- or model-specific behavior is simulated.
The design of the 1000 microinstruction set was such that executing an
instruction for which no microcode was present (e.g., executing a FFP
instruction when the FFP firmware was not installed) resulted in a NOP.
Under simulation, such execution causes an unimplemented instruction stop if
"STOP (cpu_ss_unimpl)" is non-zero and a no-operation otherwise.
*/
#include "hp2100_defs.h"
#include "hp2100_cpu.h"
#include "hp2100_cpu_dmm.h"
/* UIG 0
The first User Instruction Group (UIG) encodes firmware options for the 2100
and 1000. Instruction codes 105000-105377 are assigned to microcode options
as follows:
Instructions Option Name 2100 1000-M 1000-E 1000-F
------------- -------------------------- ------ ------ ------ ------
105000-105362 2000 I/O Processor opt - - -
105000-105137 Floating Point opt std std std
105200-105237 Fast FORTRAN Processor opt opt opt std
105240-105257 RTE-IVA/B Extended Memory - - opt opt
105240-105257 RTE-6/VM Virtual Memory - - opt opt
105300-105317 Distributed System - - opt opt
105320-105337 Double Integer - - opt -
105320-105337 Scientific Instruction Set - - - std
105340-105357 RTE-6/VM Operating System - - opt opt
If the 2100 IOP is installed, the only valid UIG instructions are IOP
instructions, as the IOP used the full 2100 microcode addressing space. The
IOP dispatcher remaps the 2100 codes to 1000 codes for execution.
The F-Series moved the three-word extended real instructions from the FFP
range to the base floating-point range and added four-word double real and
two-word double integer instructions. The double integer instructions
occupied some of the vacated extended real instruction codes in the FFP, with
the rest assigned to the floating-point range. Consequently, many
instruction codes for the F-Series are different from the E-Series.
Implementation notes:
1. Product 93585A, available from the "Specials" group, added double integer
microcode to the E-Series. The instruction codes were different from
those in the F-Series to avoid conflicting with the E-Series FFP.
2. To run the double-integer instructions diagnostic in the absence of
64-bit integer support (and therefore of F-Series simulation), a special
DBI dispatcher may be enabled by defining ENABLE_DIAG during compilation.
This dispatcher will remap the F-Series DBI instructions to the E-Series
codes, so that the F-Series diagnostic may be run. Because several of
the F-Series DBI instruction codes replace M/E-Series FFP codes, this
dispatcher will only operate if FFP is disabled.
Note that enabling the dispatcher will produce non-standard FP behavior.
For example, any code in the range 105000-105017 normally would execute a
FAD instruction. With the dispatcher enabled, 105014 would execute a
.DAD, while the other codes would execute a FAD. Therefore, ENABLE_DIAG
should only be used to run the diagnostic and is not intended for general
use.
3. Any instruction not claimed by an installed option will be sent to the
user microcode dispatcher.
*/
t_stat cpu_uig_0 (uint32 intrq, t_bool int_ack)
{
const CPU_OPTION_SET cpu_2100_iop = CPU_2100 | CPU_IOP;
if ((cpu_configuration & cpu_2100_iop) == cpu_2100_iop) /* if the CPU is a 2100 with IOP firmware installed */
return cpu_iop (intrq); /* then dispatch to the IOP executor */
#if !defined (HAVE_INT64) && defined (ENABLE_DIAG) /* special DBI diagnostic dispatcher */
if ((cpu_configuration & (CPU_FFP | CPU_DBI)) == CPU_DBI) /* if FFP is absent and DBI is present */
switch (IR & 0377) { /* then remap the F-series codes to the E-series */
case 0014: /* .DAD 105014 */
return cpu_dbi (0105321u);
case 0034: /* .DSB 105034 */
return cpu_dbi (0105327u);
case 0054: /* .DMP 105054 */
return cpu_dbi (0105322u);
case 0074: /* .DDI 105074 */
return cpu_dbi (0105325u);
case 0114: /* .DSBR 105114 */
return cpu_dbi (0105334u);
case 0134: /* .DDIR 105134 */
return cpu_dbi (0105326u);
case 0203: /* .DNG 105203 */
return cpu_dbi (0105323u);
case 0204: /* .DCO 105204 */
return cpu_dbi (0105324u);
case 0210: /* .DIN 105210 */
return cpu_dbi (0105330u);
case 0211: /* .DDE 105211 */
return cpu_dbi (0105331u);
case 0212: /* .DIS 105212 */
return cpu_dbi (0105332u);
case 0213: /* .DDS 105213 */
return cpu_dbi (0105333u);
} /* otherwise, continue */
#endif /* end of special DBI dispatcher */
switch ((IR >> 4) & 017) { /* decode IR<7:4> */
case 000: /* 105000-105017 */
case 001: /* 105020-105037 */
case 002: /* 105040-105057 */
case 003: /* 105060-105077 */
case 004: /* 105100-105117 */
case 005: /* 105120-105137 */
if (cpu_configuration & CPU_FP) /* FP option installed? */
#if defined (HAVE_INT64) /* int64 support available */
return cpu_fpp (IR); /* Floating Point Processor */
#else /* int64 support unavailable */
return cpu_fp (); /* Firmware Floating Point */
#endif /* end of int64 support */
else
break;
case 010: /* 105200-105217 */
case 011: /* 105220-105237 */
if (cpu_configuration & CPU_FFP) /* FFP option installed? */
return cpu_ffp (intrq); /* Fast FORTRAN Processor */
else
break;
case 012: /* 105240-105257 */
if (cpu_configuration & CPU_VMAOS) /* VMA/OS option installed? */
return cpu_rte_vma (); /* RTE-6 VMA */
else if (cpu_configuration & CPU_EMA) /* EMA option installed? */
return cpu_rte_ema (); /* RTE-4 EMA */
else
break;
case 014: /* 105300-105317 */
if (cpu_configuration & CPU_DS) /* DS option installed? */
return cpu_ds (); /* Distributed System */
else
break;
case 015: /* 105320-105337 */
#if defined (HAVE_INT64) /* int64 support available */
if (cpu_configuration & CPU_1000_F) /* F-series? */
return cpu_sis (IR); /* Scientific Instruction is standard */
else /* M/E-series */
#endif /* end of int64 support */
if (cpu_configuration & CPU_DBI) /* DBI option installed? */
return cpu_dbi (IR); /* Double integer */
else
break;
case 016: /* 105340-105357 */
if (cpu_configuration & CPU_VMAOS) /* VMA/OS option installed? */
return cpu_rte_os (int_ack); /* RTE-6 OS */
else
break;
}
return cpu_user (); /* try user microcode */
}
/* UIG 1
The second User Instruction Group (UIG) encodes firmware options for the
1000. Instruction codes 101400-101777 and 105400-105777 are assigned to
microcode options as follows ("x" is "1" or "5" below):
Instructions Option Name 1000-M 1000-E 1000-F
------------- ---------------------------- ------ ------ ------
10x400-10x437 2000 IOP opt opt -
10x460-10x477 2000 IOP opt opt -
10x460-10x477 Vector Instruction Set - - opt
10x520-10x537 Distributed System opt - -
10x600-10x617 SIGNAL/1000 Instruction Set - - opt
10x700-10x737 Dynamic Mapping System opt opt std
10x740-10x777 Extended Instruction Group std std std
Only 1000 systems execute these instructions.
Implementation notes:
1. The Distributed System (DS) microcode was mapped to different instruction
ranges for the M-Series and the E/F-Series. The sequence of instructions
was identical, though, so we remap the former range to the latter before
dispatching.
2. Any instruction not claimed by an installed option will be sent to the
user microcode dispatcher.
*/
t_stat cpu_uig_1 (uint32 intrq)
{
if (!(cpu_configuration & CPU_1000)) /* if the CPU is not a 1000 */
return STOP (cpu_ss_unimpl); /* the the instruction is unimplemented */
switch ((IR >> 4) & 017) { /* decode IR<7:4> */
case 000: /* 105400-105417 */
case 001: /* 105420-105437 */
if (cpu_configuration & CPU_IOP) /* IOP option installed? */
return cpu_iop (intrq); /* 2000 I/O Processor */
else
break;
case 003: /* 105460-105477 */
#if defined (HAVE_INT64) /* int64 support available */
if (cpu_configuration & CPU_VIS) /* VIS option installed? */
return cpu_vis (); /* Vector Instruction Set */
else
#endif /* end of int64 support */
if (cpu_configuration & CPU_IOP) /* IOP option installed? */
return cpu_iop (intrq); /* 2000 I/O Processor */
else
break;
case 005: /* 105520-105537 */
if (cpu_configuration & CPU_DS) { /* DS option installed? */
IR = IR ^ 0000620; /* remap to 105300-105317 */
return cpu_ds (); /* Distributed System */
}
else
break;
#if defined (HAVE_INT64) /* int64 support available */
case 010: /* 105600-105617 */
if (cpu_configuration & CPU_SIGNAL) /* SIGNAL option installed? */
return cpu_signal (); /* SIGNAL/1000 Instructions */
else
break;
#endif /* end of int64 support */
case 014: /* 105700-105717 */
case 015: /* 105720-105737 */
if (cpu_configuration & CPU_DMS) /* DMS option installed? */
return cpu_dms (intrq); /* Dynamic Mapping System */
else
break;
case 016: /* 105740-105757 */
case 017: /* 105760-105777 */
return cpu_eig (IR, intrq); /* Extended Instruction Group */
}
return cpu_user (); /* try user microcode */
}
/* Distributed System.
Distributed System firmware was provided with the HP 91740A DS/1000 product
for use with the HP 12771A (12665A) Serial Interface and 12773A Modem
Interface system interconnection kits. Firmware permitted high-speed
transfers with minimum impact to the processor. The advent of the
"intelligent" 12794A and 12825A HDLC cards, the 12793A and 12834A Bisync
cards, and the 91750A DS-1000/IV software obviated the need for CPU firmware,
as essentially the firmware was moved onto the I/O cards.
Primary documentation for the DS instructions has not been located. However,
examination of the DS/1000 sources reveals that two instruction were used by
the DVA65 Serial Interface driver (91740-18071) and placed in the trap cells
of the communications interfaces. Presumably they handled interrupts from
the cards.
Implementation of the DS instructions will also require simulation of the
12665A Hardwired Serial Data Interface Card.
Option implementation by CPU was as follows:
2114 2115 2116 2100 1000-M 1000-E 1000-F
------ ------ ------ ------ ------ ------ ------
N/A N/A N/A N/A 91740A 91740B 91740B
The routines are mapped to instruction codes as follows:
Instr. 1000-M 1000-E/F Description
------ ------ -------- ----------------------------------------------
105520 105300 "Open loop" (trap cell handler)
105521 105301 "Closed loop" (trap cell handler)
105522 105302 [unknown]
[test] 105524 105304 [self test]
-- 105310 7974 boot loader ROM extension
Notes:
1. The E/F-Series opcodes were moved from 105340-357 to 105300-317 at
revision 1813.
2. DS/1000 ROM data are available from Bitsavers.
Additional references (documents unavailable):
- HP 91740A M-Series Distributed System (DS/1000) Firmware Installation
Manual (91740-90007).
- HP 91740B Distributed System (DS/1000) Firmware Installation Manual
(91740-90009).
*/
static const OP_PAT op_ds[16] = {
OP_N, OP_N, OP_N, OP_N, /* --- --- --- --- */
OP_N, OP_N, OP_N, OP_N, /* --- --- --- --- */
OP_N, OP_N, OP_N, OP_N, /* --- --- --- --- */
OP_N, OP_N, OP_N, OP_N /* --- --- --- --- */
};
t_stat cpu_ds (void)
{
t_stat reason = SCPE_OK;
OPS op;
uint32 entry;
entry = IR & 017; /* mask to entry point */
if (op_ds [entry] != OP_N) {
reason = cpu_ops (op_ds[entry], op); /* get instruction operands */
if (reason != SCPE_OK) /* did the evaluation fail? */
return reason; /* return the reason for failure */
}
switch (entry) { /* decode IR<3:0> */
default: /* others unimplemented */
reason = STOP (cpu_ss_unimpl);
}
return reason;
}
/* User firmware dispatcher.
All UIG instructions unclaimed by installed firmware options are directed
here. User- or site-specific firmware may be simulated by dispatching to the
appropriate simulator routine. Unimplemented instructions should return
"STOP (cpu_ss_unimpl)" to cause a simulator stop if enabled.
Implementation notes:
1. This routine may be passed any opcode in the ranges 101400-101737 and
105000-105737. The 10x740-777 range is dedicated to the EIG instructions
and is unavailable for user microprograms.
2. HP operating systems and subsystems depend on the following instructions
to execute as NOP and return success if the corresponding firmware is not
installed:
105226 -- Fast FORTRAN Processor .FLUN instruction
105355 -- RTE-6/VM OS self-test instruction
105477 -- Vector Instruction Set self-test
105617 -- SIGNAL/1000 self-test
These instructions are executed to determine firmware configuration
dynamically. If you use any of these opcodes for your own use, be aware
that certain HP programs may fail.
3. User microprograms occupied one or more firmware modules, each containing
16 potential instruction entry points. A skeleton dispatcher for the 32
possible modules is implemented below, along with a sample module.
*/
static t_stat cpu_user_20 (void); /* [0] Module 20 user microprograms stub */
t_stat cpu_user (void)
{
t_stat reason = SCPE_OK;
if (cpu_configuration & CPU_211X) /* 2116/15/14 CPU? */
return STOP (cpu_ss_unimpl); /* user microprograms not supported */
switch ((IR >> 4) & 037) { /* decode IR<8:4> */
/* case 000: ** 105000-105017 */
/* return cpu_user_00 (); ** uncomment to handle instruction */
/* case 001: ** 105020-105037 */
/* return cpu_user_01 (); ** uncomment to handle instruction */
/* case 0nn: ** other cases as needed */
/* return cpu_user_nn (); ** uncomment to handle instruction */
case 020: /* 10x400-10x417 */
return cpu_user_20 (); /* call sample dispatcher */
/* case 021: ** 10x420-10x437 */
/* return cpu_user_21 (); ** uncomment to handle instruction */
/* case 0nn: ** other cases as needed */
/* return cpu_user_nn (); ** uncomment to handle instruction */
default: /* others unimplemented */
reason = STOP (cpu_ss_unimpl);
}
return reason;
}
/* Example user microprogram simulator.
User- or site-specific firmware may be simulated by writing the appropriate
code below. Unimplemented instructions should return "STOP (cpu_ss_unimpl)"
to cause a simulator stop if enabled.
For information on the operand patterns used in the "op_user" array, see the
comments preceding the "cpu_ops" routine in "hp2100_cpu1.c" and the "operand
processing encoding" constants in "hp2100_cpu1.h".
*/
static const OP_PAT op_user_20[16] = {
OP_N, OP_N, OP_N, OP_N, /* --- --- --- --- */
OP_N, OP_N, OP_N, OP_N, /* --- --- --- --- */
OP_N, OP_N, OP_N, OP_N, /* --- --- --- --- */
OP_N, OP_N, OP_N, OP_N /* --- --- --- --- */
};
static t_stat cpu_user_20 (void)
{
t_stat reason = SCPE_OK;
OPS op;
uint32 entry;
entry = IR & 017; /* mask to entry point */
if (op_user_20 [entry] != OP_N) {
reason = cpu_ops (op_user_20 [entry], op); /* get instruction operands */
if (reason != SCPE_OK) /* did the evaluation fail? */
return reason; /* return the reason for failure */
}
switch (entry) { /* decode IR<4:0> */
case 000: /* 10x400 */
/* break; ** uncomment to handle instruction */
case 001: /* 10x401 */
/* break; ** uncomment to handle instruction */
/* case 0nn: ** other cases as needed */
/* break; ** uncomment to handle instruction */
default: /* others unimplemented */
reason = STOP (cpu_ss_unimpl);
}
return reason;
}
/* Read a multiple-precision operand value */
OP ReadOp (HP_WORD va, OPSIZE precision)
{
OP operand;
uint32 i;
if (precision == in_s)
operand.word = ReadW (va); /* read single integer */
else if (precision == in_d)
operand.dword = ReadW (va) << 16 | /* read double integer */
ReadW ((va + 1) & LA_MASK); /* merge high and low words */
else
for (i = 0; i < (uint32) precision; i++) { /* read fp 2 to 5 words */
operand.fpk[i] = ReadW (va);
va = (va + 1) & LA_MASK;
}
return operand;
}
/* Write a multiple-precision operand value */
void WriteOp (HP_WORD va, OP operand, OPSIZE precision)
{
uint32 i;
if (precision == in_s)
WriteW (va, operand.word); /* write single integer */
else if (precision == in_d) {
WriteW (va, UPPER_WORD (operand.dword)); /* write double integer */
WriteW (va + 1 & LA_MASK, LOWER_WORD (operand.dword)); /* high word, then low word */
}
else
for (i = 0; i < (uint32) precision; i++) { /* write fp 2 to 5 words */
WriteW (va, operand.fpk[i]);
va = (va + 1) & LA_MASK;
}
return;
}
/* Get instruction operands.
Operands for a given instruction are specifed by an "operand pattern"
consisting of flags indicating the types and storage methods. The pattern
directs how each operand is to be retrieved and whether the operand value or
address is returned in the operand array.
Typically, a microcode simulation handler will define an OP_PAT array, with
each element containing an operand pattern corresponding to the simulated
instruction. Operand patterns are defined in the header file accompanying
this source file. After calling this function with the appropriate operand
pattern and a pointer to an array of OPs, operands are decoded and stored
sequentially in the array.
The following operand encodings are defined:
Code Operand Description Example Return
------ ---------------------------------------- ----------- ------------
OP_NUL No operand present [inst] None
OP_IAR Integer constant in A register LDA I Value of I
[inst]
...
I DEC 0
OP_JAB Double integer constant in A/B registers DLD J Value of J
[inst]
...
J DEC 0,0
OP_FAB 2-word FP constant in A/B registers DLD F Value of F
[inst]
...
F DEC 0.0
OP_CON Inline 1-word constant [inst] Value of C
C DEC 0
...
OP_VAR Inline 1-word variable [inst] Address of V
V BSS 1
...
OP_ADR Inline address [inst] Address of A
DEF A
...
A EQU *
OP_ADK Address of integer constant [inst] Value of K
DEF K
...
K DEC 0
OP_ADD Address of double integer constant [inst] Value of D
DEF D
...
D DEC 0,0
OP_ADF Address of 2-word FP constant [inst] Value of F
DEF F
...
F DEC 0.0
OP_ADX Address of 3-word FP constant [inst] Value of X
DEF X
...
X DEX 0.0
OP_ADT Address of 4-word FP constant [inst] Value of T
DEF T
...
T DEY 0.0
OP_ADE Address of 5-word FP constant [inst] Value of E
DEF E
...
E DEC 0,0,0,0,0
Address operands, i.e., those having a DEF to the operand, will be resolved
to direct addresses. If an interrupt is pending and more than three levels
of indirection are used, the routine returns without completing operand
retrieval (the instruction will be retried after interrupt servicing).
Addresses are always resolved in the current DMS map.
An operand pattern consists of one or more operand encodings, corresponding
to the operands required by a given instruction. Values are returned in
sequence to the operand array.
*/
t_stat cpu_ops (OP_PAT pattern, OPS op)
{
OP_PAT flags;
uint32 i;
t_stat reason = SCPE_OK;
for (i = 0; i < OP_N_F; i++) {
flags = pattern & OP_M_FLAGS; /* get operand pattern */
if (flags >= OP_ADR) { /* address operand? */
MR = ReadW (PR); /* get the pointer */
reason = cpu_resolve_indirects (TRUE); /* resolve indirects */
if (reason != SCPE_OK) /* resolution failed? */
return reason;
}
switch (flags) {
case OP_NUL: /* null operand */
return reason; /* no more, so quit */
case OP_IAR: /* int in A */
(*op++).word = AR; /* get one-word value */
break;
case OP_JAB: /* dbl-int in A/B */
(*op++).dword = (AR << 16) | BR; /* get two-word value */
break;
case OP_FAB: /* 2-word FP in A/B */
(*op).fpk[0] = AR; /* get high FP word */
(*op++).fpk[1] = BR; /* get low FP word */
break;
case OP_CON: /* inline constant operand */
*op++ = ReadOp (PR, in_s); /* get value */
break;
case OP_VAR: /* inline variable operand */
(*op++).word = PR; /* get pointer to variable */
break;
case OP_ADR: /* inline address operand */
(*op++).word = MR; /* get address (set by "resolve" above) */
break;
case OP_ADK: /* address of int constant */
*op++ = ReadOp (MR, in_s); /* get value */
break;
case OP_ADD: /* address of dbl-int constant */
*op++ = ReadOp (MR, in_d); /* get value */
break;
case OP_ADF: /* address of 2-word FP const */
*op++ = ReadOp (MR, fp_f); /* get value */
break;
case OP_ADX: /* address of 3-word FP const */
*op++ = ReadOp (MR, fp_x); /* get value */
break;
case OP_ADT: /* address of 4-word FP const */
*op++ = ReadOp (MR, fp_t); /* get value */
break;
case OP_ADE: /* address of 5-word FP const */
*op++ = ReadOp (MR, fp_e); /* get value */
break;
default:
return SCPE_IERR; /* not implemented */
}
if (flags >= OP_CON) /* operand after instruction? */
PR = (PR + 1) & LA_MASK; /* yes, so bump to next */
pattern = pattern >> OP_N_FLAGS; /* move next pattern into place */
}
return reason;
}