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-rw-r--r--avr/z80-if.c232
1 files changed, 153 insertions, 79 deletions
diff --git a/avr/z80-if.c b/avr/z80-if.c
index 4544997..cc0bab1 100644
--- a/avr/z80-if.c
+++ b/avr/z80-if.c
@@ -2,57 +2,58 @@
*
* Pin assignments
*
- * | Z180-Sig | AVR-Port | Dir | Special Function |
+ * | Z180-Sig | AVR-Port | Dir | Special Function |
* +------------+---------------+-------+-----------------------+
- * | A0 | PA 0 | O | |
- * | A1 | PA 1 | O | |
- * | A2 | PA 2 | O | |
- * | A3 | PA 3 | O | |
- * | A4 | PA 4 | O | |
- * | A5 | PA 5 | O | |
- * | A6 | PA 6 | O | |
- * | A7 | PA 7 | O | |
- * | A8 | PC 0 | O | |
- * | A9 | PC 1 | O | |
- * | A10 | PC 2 | O | |
- * | A11 | PC 3 | O | |
- * | A12 | PC 4 | O | |
- * | A13 | PC 5 | O | |
- * | A14 | PC 6 | O | |
- * | A15 | PC 7 | O | |
- * | A16 | PE 2 | O | |
- * | A17 | PE 3 | O | |
- * | A18 | PE 4 | O | |
- * | D0 | PF 0 | I/O | |
- * | D1 | PF 1 | I/O | |
- * | D2 | PF 2 | I/O | |
- * | D3 | PF 3 | I/O | |
- * | D4 | PF 4 | I/O | |
- * | D5 | PF 5 | I/O | |
- * | D6 | PF 6 | I/O | |
- * | D7 | PF 7 | I/O | |
- * | RD | PD 3 | O | |
- * | WR | PD 2 | O | |
- * | MREQ | PD 4 | O | |
- * | RST | PD 5 | O | |
- * | BUSREQ | PD 7 | O | |
- * | BUSACK | PD 6 | I | |
- * | IOCS1 | PE 5 | I | |
- * |* HALT | P | | |
- * |* NMI | P | | |
- * | | P | | |
- * | | P | | af1 USART1_TX |
- * | | P | | af1 USART1_RX |
- * | | P |JTDI | remap SPI1_NSS' |
- * | | P |JTDO | remap SPI1_SCK' |
- * | | P |JTRST | remap SPI1_MISO' |
- * | | P | | remap SPI1_MOSI' |
- * | | P | | af1 OSC32 |
- * | | P | | af1 OSC32 |
+ * | A0 | PA 0 | O | |
+ * | A1 | PA 1 | O | |
+ * | A2 | PA 2 | O | |
+ * | A3 | PA 3 | O | |
+ * | A4 | PA 4 | O | |
+ * | A5 | PA 5 | O | |
+ * | A6 | PA 6 | O | |
+ * | A7 | PA 7 | O | |
+ * | A8 | PC 0 | O | |
+ * | A9 | PC 1 | O | |
+ * | A10 | PC 2 | O | |
+ * | A11 | PC 3 | O | |
+ * | A12 | PC 4 | O | |
+ * | A13 | PC 5 | O | |
+ * | A14 | PC 6 | O | |
+ * | A15 | PC 7 | O | |
+ * | A16 | PE 2 | O | |
+ * | A17 | PE 3 | O | |
+ * | A18 | PE 4 | O | |
+ * | D0 | PF 0 | I/O | |
+ * | D1 | PF 1 | I/O | |
+ * | D2 | PF 2 | I/O | |
+ * | D3 | PF 3 | I/O | |
+ * | D4 | PF 4 | I/O | |
+ * | D5 | PF 5 | I/O | |
+ * | D6 | PF 6 | I/O | |
+ * | D7 | PF 7 | I/O | |
+ * | RD | PD 3 | O | |
+ * | WR | PD 2 | O | |
+ * | MREQ | PD 4 | O | |
+ * | RST | PD 5 | O | |
+ * | BUSREQ | PD 7 | O | |
+ * | BUSACK | PD 6 | I | |
+ * | IOCS1 | PE 5 | I | |
+ * |* HALT | P | | |
+ * |* NMI | P | | |
+ * | | P | | |
+ * | | P | | af1 USART1_TX |
+ * | | P | | af1 USART1_RX |
+ * | | P |JTDI | remap SPI1_NSS' |
+ * | | P |JTDO | remap SPI1_SCK' |
+ * | | P |JTRST | remap SPI1_MISO' |
+ * | | P | | remap SPI1_MOSI' |
+ * | | P | | af1 OSC32 |
+ * | | P | | af1 OSC32 |
*/
+
#include "common.h"
#include <util/atomic.h>
#include "debug.h"
@@ -117,6 +118,9 @@
//#define Z80_I_HALT SBIT(P_HALT, )
+#define BUS_TO 20
+
+
#define MASK(n) ((1<<(n))-1)
#define SMASK(w,s) (MASK(w) << (s))
@@ -129,6 +133,20 @@ typedef union {
static zstate_t zstate;
+static volatile uint8_t timer; /* used for bus timeout */
+
+/*---------------------------------------------------------*/
+/* 10Hz timer interrupt generated by OC4A */
+/*---------------------------------------------------------*/
+
+ISR(TIMER4_COMPA_vect)
+{
+
+ uint8_t i = timer;
+
+ if (i)
+ timer = i - 1;
+}
/*--------------------------------------------------------------------------*/
@@ -207,6 +225,13 @@ void z80_setup_bus(void)
z80_dbus_set_in();
zstate = RESET;
+
+ /* Timer 4 */
+ PRR1 &= ~_BV(PRTIM4);
+ OCR4A = F_CPU / 1024 / 10 - 1; /* Timer: 10Hz interval (OC4A) */
+ TCCR4B = (0b01<<WGM42)|(0b101<<CS30); /* CTC Mode, Prescaler 1024 */
+ TIMSK4 = _BV(OCIE4A); /* Enable oca interrupt */
+
}
@@ -228,40 +253,42 @@ static void z80_busreq_hpulse(void)
}
if (zstate & ZST_ACQUIRED) {
- while(Z80_I_BUSACK == 1)
+ timer = BUS_TO;
+ while (Z80_I_BUSACK == 1 && timer)
;
- z80_addrbus_set_active();
+ if (Z80_I_BUSACK == 0)
+ z80_addrbus_set_active();
}
}
/*
- + | | | | |
+ + | | | | |
+ State | RESET | RESET_AQRD | RUNNING | RUNNING_AQRD |
- + | | | | |
- + | 0 | 1 | 2 | 3 |
-Event + | | | | |
+ + | | | | |
+ + | 0 | 1 | 2 | 3 |
+Event + | | | | |
----------------+---------------+---------------+---------------+---------------+
- | | | | |
-Reset | 0 | 0 | 0 | 0 |
- | | | | |
- | | | | |
-Request | 1 | | 3 | |
- | | | | |
- | | | | |
-Release | | 0 | | 2 |
- | | | | |
- | | | | |
-Run | 2 | 3 | | |
- | | | | |
- | | | | |
-Restart | | | 2 | 3 |
- | | | | |
- | | | | |
-M_Cycle | | | | 3 |
- | | | | |
- | | | | |
+ | | | | |
+Reset | 0 | 0 | 0 | 0 |
+ | | | | |
+ | | | | |
+Request | 1 | | 3 | |
+ | | | | |
+ | | | | |
+Release | | 0 | | 2 |
+ | | | | |
+ | | | | |
+Run | 2 | 3 | | |
+ | | | | |
+ | | | | |
+Restart | | | 2 | 3 |
+ | | | | |
+ | | | | |
+M_Cycle | | | | 3 |
+ | | | | |
+ | | | | |
*/
zstate_t z80_bus_cmd(bus_cmd_t cmd)
@@ -281,18 +308,29 @@ zstate_t z80_bus_cmd(bus_cmd_t cmd)
case RESET:
Z80_O_BUSREQ = 0;
Z80_O_RST = 1;
- while(Z80_I_BUSACK == 1)
+ timer = BUS_TO;
+ while (Z80_I_BUSACK == 1 && timer)
;
- z80_addrbus_set_active();
- zstate = RESET_AQRD;
+ if (Z80_I_BUSACK == 0) {
+ z80_addrbus_set_active();
+ zstate = RESET_AQRD;
+ } else {
+ Z80_O_RST = 0;
+ Z80_O_BUSREQ = 1;
+ }
break;
case RUNNING:
Z80_O_BUSREQ = 0;
- while(Z80_I_BUSACK == 1)
+ timer = BUS_TO;
+ while (Z80_I_BUSACK == 1 && timer)
;
- z80_addrbus_set_active();
- zstate = RUNNING_AQRD;
+ if (Z80_I_BUSACK == 0) {
+ z80_addrbus_set_active();
+ zstate = RUNNING_AQRD;
+ } else {
+ Z80_O_BUSREQ = 1;
+ }
break;
default:
@@ -353,7 +391,7 @@ zstate_t z80_bus_cmd(bus_cmd_t cmd)
case M_Cycle:
switch (zstate) {
case RUNNING_AQRD:
- z80_busreq_hpulse();
+ z80_busreq_hpulse(); /* TODO: */
break;
default:
break;
@@ -411,8 +449,25 @@ void z80_memset(uint32_t addr, uint8_t data, uint32_t length)
{
z80_dbus_set_out();
Z80_O_MREQ = 0;
+ P_DB = data;
while(length--) {
z80_setaddress(addr++);
+ Z80_O_WR = 0;
+ Z80_O_WR = 0;
+ Z80_O_WR = 1;
+ }
+ Z80_O_MREQ = 1;
+}
+
+void z80_write_block_P(const FLASH uint8_t *src, uint32_t dest, uint32_t length)
+{
+ uint8_t data;
+
+ z80_dbus_set_out();
+ Z80_O_MREQ = 0;
+ while(length--) {
+ z80_setaddress(dest++);
+ data = *src++;
P_DB = data;
P_DB = data;
Z80_O_WR = 0;
@@ -422,7 +477,7 @@ void z80_memset(uint32_t addr, uint8_t data, uint32_t length)
Z80_O_MREQ = 1;
}
-void z80_write_block(const __flash uint8_t *src, uint32_t dest, uint32_t length)
+void z80_write_block(const uint8_t *src, uint32_t dest, uint32_t length)
{
uint8_t data;
@@ -440,6 +495,25 @@ void z80_write_block(const __flash uint8_t *src, uint32_t dest, uint32_t length)
Z80_O_MREQ = 1;
}
+void z80_read_block (uint8_t *dest, uint32_t src, size_t length)
+{
+ uint8_t data;
+
+ Z80_O_MREQ = 0;
+ z80_dbus_set_in();
+ while(length--) {
+ z80_setaddress(src++);
+ Z80_O_RD = 0;
+ Z80_O_RD = 0;
+ Z80_O_RD = 0;
+ data = PIN_DB;
+ Z80_O_RD = 1;
+ *dest++ = data;
+ }
+ Z80_O_MREQ = 1;
+}
+
+
/*
0179' rx.bs_mask: ds 1 ; (buf_len - 1)
017A' rx.in_idx: ds 1 ;
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-01 16:31:03 +0000