From 2153fedd8dbe2b409808188dbdf0e1b0eedce36b Mon Sep 17 00:00:00 2001
From: folkert van heusden <mail@vanheusden.com>
Date: Mon, 20 May 2024 21:50:14 +0200
Subject: [PATCH] Configurable line hz

---
 debugger.cpp | 13 +++++++++++++
 kw11-l.cpp   | 39 +++++++++++++++++++++++++++++++++++----
 kw11-l.h     |  3 +++
 3 files changed, 51 insertions(+), 4 deletions(-)

diff --git a/debugger.cpp b/debugger.cpp
index 6aca163..ed529d5 100644
--- a/debugger.cpp
+++ b/debugger.cpp
@@ -710,6 +710,14 @@ void deserdc11(console *const cnsl, bus *const b)
 	cnsl->put_string_lf(format("Deserialized " SERIAL_CFG_FILE));
 }
 
+void set_kw11_l_interrupt_freq(console *const cnsl, bus *const b, const int freq)
+{
+	if (freq >= 1 && freq < 1000)
+		b->getKW11_L()->set_interrupt_frequency(freq);
+	else
+		cnsl->put_string_lf("Frequency out of range");
+}
+
 void debugger(console *const cnsl, bus *const b, std::atomic_uint32_t *const stop_event)
 {
 	int32_t trace_start_addr = -1;
@@ -1062,6 +1070,10 @@ void debugger(console *const cnsl, bus *const b, std::atomic_uint32_t *const sto
 				continue;
 			}
 #endif
+			else if (parts[0] == "setinthz" && parts.size() == 2) {
+				set_kw11_l_interrupt_freq(cnsl, b, std::stoi(parts.at(1)));
+				continue;
+			}
 			else if (parts[0] == "setsl" && parts.size() == 3) {
 				if (setloghost(parts.at(1).c_str(), parse_ll(parts[2])) == false)
 					cnsl->put_string_lf("Failed parsing IP address");
@@ -1183,6 +1195,7 @@ void debugger(console *const cnsl, bus *const b, std::atomic_uint32_t *const sto
 					"setpc x       - set PC to value",
 					"setmem ...    - set memory (a=) to value (v=), both in octal, one byte",
 					"toggle ...    - set switch (s=, 0...15 (decimal)) of the front panel to state (t=, 0 or 1)",
+					"setinthz x    - set KW11-L interrupt frequency (Hz)",
 					"cls           - clear screen",
 					"dir           - list files",
 					"bic x         - run BIC/LDA file",
diff --git a/kw11-l.cpp b/kw11-l.cpp
index 7ea882d..f044f84 100644
--- a/kw11-l.cpp
+++ b/kw11-l.cpp
@@ -92,15 +92,31 @@ void kw11_l::operator()()
 		if (*cnsl->get_running_flag()) {
 			myusleep(1000000 / 100);  // 100 Hz
 
+			int cur_int_freq = 1;
+
+			{
+#if defined(BUILD_FOR_RP2040)
+				xSemaphoreTake(lf_csr_lock, portMAX_DELAY);
+#else
+				std::unique_lock<std::mutex> lck(lf_csr_lock);
+#endif
+
+				cur_int_freq = int_frequency;
+
+#if defined(BUILD_FOR_RP2040)
+				xSemaphoreGive(lf_csr_lock);
+#endif
+			}
+
 			uint64_t current_cycle_count = b->getCpu()->get_instructions_executed_count();
 			uint32_t took_ms = b->getCpu()->get_effective_run_time(current_cycle_count - prev_cycle_count);
 			auto     now     = get_ms();
 
-			// - 50 Hz depending on instrution count
+			// - 50 Hz depending on instruction count ('cur_int_freq')
 			// - nothing executed in interval
-			// - 10 Hz minimum
+			// - 2 Hz minimum
 			auto t_diff = now - prev_tick;
-			if (took_ms >= 1000 / 50 || current_cycle_count - interval_prev_cycle_count == 0 || t_diff >= 100) {
+			if (took_ms >= 1000 / cur_int_freq || current_cycle_count - interval_prev_cycle_count == 0 || t_diff >= 500) {
 				do_interrupt();
 
 				prev_cycle_count = current_cycle_count;
@@ -137,12 +153,27 @@ uint16_t kw11_l::read_word(const uint16_t a)
 	uint16_t temp = lf_csr;
 
 #if defined(BUILD_FOR_RP2040)
-       	xSemaphoreGive(lf_csr_lock);
+	xSemaphoreGive(lf_csr_lock);
 #endif
 
 	return temp;
 }
 
+void kw11_l::set_interrupt_frequency(const int Hz)
+{
+#if defined(BUILD_FOR_RP2040)
+	xSemaphoreTake(lf_csr_lock, portMAX_DELAY);
+#else
+	std::unique_lock<std::mutex> lck(lf_csr_lock);
+#endif
+
+	int_frequency = Hz;
+
+#if defined(BUILD_FOR_RP2040)
+	xSemaphoreGive(lf_csr_lock);
+#endif
+}
+
 void kw11_l::write_byte(const uint16_t addr, const uint8_t value)
 {
 	if (addr != ADDR_LFC) {
diff --git a/kw11-l.h b/kw11-l.h
index f921bd3..995c482 100644
--- a/kw11-l.h
+++ b/kw11-l.h
@@ -23,6 +23,7 @@ private:
 	std::thread       *th         { nullptr };
 	std::mutex         lf_csr_lock;
 #endif
+	int                int_frequency { 50   };
 	uint16_t           lf_csr     { 0       };
 
 	int64_t            t_diff_sum { 0       };
@@ -43,6 +44,8 @@ public:
 
 	void     show_state(console *const cnsl) const override;
 
+	void     set_interrupt_frequency(const int Hz);
+
 	JsonDocument serialize();
 	static kw11_l *deserialize(const JsonVariantConst j, bus *const b, console *const cnsl);