ew debug command: xx busack: Measure time RESET to BUSACK

4 files changed, 81 insertions, 19 deletions

diff --git a/avr/cmd_cpu.c b/avr/cmd_cpu.c
index 1b1982c..1627d9f 100644
--- a/avr/cmd_cpu.c
+++ b/avr/cmd_cpu.c
@@ -97,7 +97,7 @@ static void	test_delay(uint32_t count)
 {
 	uint32_t ts = get_timer(0);
 
-	while (get_timer(ts) < count);
+	while (get_timer(ts) <= count);
 }
 
 command_ret_t do_cpu_test(cmd_tbl_t *cmdtp UNUSED, uint_fast8_t flag UNUSED, int argc, char * const argv[])
@@ -133,6 +133,31 @@ command_ret_t do_cpu_test(cmd_tbl_t *cmdtp UNUSED, uint_fast8_t flag UNUSED, int
 	return CMD_RET_SUCCESS;
 }
 
+command_ret_t do_busack_test(cmd_tbl_t *cmdtp UNUSED, uint_fast8_t flag UNUSED, int argc UNUSED, char * const argv[] UNUSED)
+{
+
+	if ((z80_bus_state() & ZST_ACQUIRED) != RESET)
+		cmd_error(CMD_RET_FAILURE, ERUNNING, NULL);
+
+	z80_bus_cmd(Request);
+	uint32_t result = z80_get_busreq_cycles();
+	test_delay(20);
+	z80_bus_cmd(Release);
+
+#if 0
+	long div;
+
+	pinconf = gpio_config_get(pin);
+	if (pinconf == OUTPUT_TIMER) {
+		div = gpio_clockdiv_get(pin);
+#endif
+
+
+	printf_P(PSTR("cycles: %lu, time: %luus\n"), result, (uint32_t) (result * 1000000LL / F_CPU));
+
+	return CMD_RET_SUCCESS;
+}
+
 #if 0
 command_ret_t do_cpu_freq(cmd_tbl_t *cmdtp UNUSED, int flag UNUSED, int argc, char * const argv[])
 {
@@ -250,6 +275,11 @@ CMD_TBL_ITEM(
 	"Do bus request/release cycles",
 	"[-t pulsewidth]"
 ),
+CMD_TBL_ITEM(
+	busack,	2,	1,	do_busack_test,
+	"Get time from /Reset high to /BUSACK low",
+	""
+),
 #if 0
 CMD_TBL_ITEM(
 	freq,	CONFIG_SYS_MAXARGS,	1,	do_cpu_freq,
diff --git a/avr/strerror.c b/avr/strerror.c
index a4d2a67..199504a 100644
--- a/avr/strerror.c
+++ b/avr/strerror.c
@@ -10,18 +10,18 @@
 
 static const FLASH char * const FLASH error_strings[] = {
 	FSTR("Unknown error"),
-	FSTR("Not enough memory"),
-	FSTR("Interrupt"),
-	FSTR("Bus timeout"),
-	FSTR("Unexpected argument"),
-	FSTR("Invalid disk number"),
-	FSTR("Disk already attached"),
-	FSTR("Disk not attached"),
-	FSTR("Error opening file"),
-	FSTR("File already attached to other drive"),
-	FSTR("CPU is running"),
-	FSTR("Invalid argument"),
-	FSTR("Unexpected EOF"),
+	FSTR("Not enough memory"),						/* 101 */
+	FSTR("Interrupt"),                              /* 102 */
+	FSTR("Bus timeout"),                            /* 103 */
+	FSTR("Unexpected argument"),                    /* 104 */
+	FSTR("Invalid disk number"),                    /* 105 */
+	FSTR("Disk already attached"),                  /* 106 */
+	FSTR("Disk not attached"),                      /* 107 */
+	FSTR("Error opening file"),                     /* 108 */
+	FSTR("File already attached to other drive"),   /* 109 */
+	FSTR("CPU is running"),                         /* 110 */
+	FSTR("Invalid argument"),                       /* 111 */
+	FSTR("Unexpected EOF"),                         /* 112 */
 
 };
 
diff --git a/avr/z80-if.c b/avr/z80-if.c
index 5d88842..62199bb 100644
--- a/avr/z80-if.c
+++ b/avr/z80-if.c
@@ -145,14 +145,15 @@ void z80_bus_request_or_exit(void)
 static zstate_t zstate;
 static volatile uint8_t timer;		/* used for bus timeout */
 
-#if 0
-static volatile uint16_t req_cycles_ovl;
+
+static volatile uint16_t busack_cycles_ovl;
+
+static uint32_t busack_cycles;
 
 ISR(TIMER4_COMPB_vect)
 {
-	req_cycles_ovl++;
+	busack_cycles_ovl++;
 }
-#endif
 
 /*---------------------------------------------------------*/
 /* 10Hz timer interrupt generated by OC5A                  */
@@ -282,6 +283,11 @@ void z80_setup_bus(void)
 }
 
 
+uint32_t z80_get_busreq_cycles(void)
+{
+	return busack_cycles;
+}
+
 zstate_t z80_bus_state(void)
 {
 	return zstate;
@@ -373,13 +379,38 @@ zstate_t z80_bus_cmd(bus_cmd_t cmd)
 		switch (zstate) {
 		case RESET:
 			Z80_O_BUSREQ = 0;
-			z80_reset_inactive();
-			timer = BUS_TO;
+			timer = 255; //BUS_TO;
+
+			uint16_t tcnt;
+			uint16_t ovl_cnt;
+			uint8_t ifr;
+			busack_cycles = 0;
+			busack_cycles_ovl = 0;
+			ATOMIC_BLOCK(ATOMIC_FORCEON) {
+				//z80_reset_inactive();
+				Z80_I_RST = 1;					/* Toggle RESET  --> inactive */
+				OCR4B = TCNT4;
+				TIFR4 = _BV(OCF4B);				/* Clear compare match flag */
+			}
+			TIMSK4 |= _BV(OCIE4B);				/* Enable compare match interrupt */
+
 			while (Z80_I_BUSACK == 1 && timer)
 				;
+
+			ATOMIC_BLOCK(ATOMIC_FORCEON) {
+				tcnt = TCNT4 - OCR4B;
+				ovl_cnt = busack_cycles_ovl;
+				ifr = TIFR4;
+				TIMSK4 &= ~_BV(OCIE4B);			/* Disable compare match interrupt */
+			}
 			if (Z80_I_BUSACK == 0) {
+				if ((ifr & _BV(OCF4B)) && !(tcnt & (1<<15)))
+					ovl_cnt++;
+				busack_cycles = tcnt + ((uint32_t) ovl_cnt << 16);
 				z80_addrbus_set_out();
 				zstate = RESET_AQRD;
+//				debug("### ovl: %u, ifr: %u, beg: %u, end: %u\n", ovl_cnt,
+//								(ifr & _BV(OCF4B)) != 0,	OCR4B, tcnt);
 			} else {
 				z80_reset_active();
 				Z80_O_BUSREQ = 1;
diff --git a/include/z80-if.h b/include/z80-if.h
index 7225cf4..a431500 100644
--- a/include/z80-if.h
+++ b/include/z80-if.h
@@ -29,6 +29,7 @@ typedef enum {LOW, HIGH} level_t;
 
 void z80_bus_request_or_exit(void);
 
+uint32_t z80_get_busreq_cycles(void);
 zstate_t z80_bus_state(void);
 zstate_t z80_bus_cmd(bus_cmd_t cmd);
 void z80_setup_bus(void);