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Diffstat (limited to 'avr/z80-if.c')
-rw-r--r--avr/z80-if.c127
1 files changed, 54 insertions, 73 deletions
diff --git a/avr/z80-if.c b/avr/z80-if.c
index 955a61a..207aed1 100644
--- a/avr/z80-if.c
+++ b/avr/z80-if.c
@@ -95,6 +95,7 @@ struct bits {
#define BUSREQ 7
#define DDR_BUSREQ DDRD
#define P_BUSACK PORTD
+#define PIN_BUSACK PIND
#define BUSACK 6
#define DDR_BUSACK DDRD
//#define P_HALT PORTA
@@ -117,8 +118,8 @@ struct bits {
#define P_ADH PORTC
#define P_ADB PORTE
#define PIN_ADB PINE
-#define DDR_ADL DDRE
-#define DDR_ADH DDRE
+#define DDR_ADL DDRA
+#define DDR_ADH DDRC
#define DDR_ADB DDRE
#define ADB_WIDTH 3
@@ -126,49 +127,16 @@ struct bits {
//#define ADB_PORT PORTE
-
-#define ADp1_OFS 0
-#define ADp1_WIDTH 8
-#define ADp1_SHIFT 1
-#define ADp1_PORT GPIOA
-
-#define ADp2_OFS ADp1_WIDTH
-#define ADp2_WIDTH 8
-#define ADp2_SHIFT 0
-#define ADp2_PORT GPIOC
-
-#define ADp3_OFS (ADp2_OFS+ADp2_WIDTH)
-#define ADp3_WIDTH 3
-#define ADp3_SHIFT 10
-#define ADp3_PORT GPIOC
-
-#define ADunbuff1_WIDTH 1
-#define ADunbuff1_SHIFT 8
-#define ADunbuff1_PORT GPIOA
-
-#define ADunbuff2_WIDTH 2
-#define ADunbuff2_SHIFT 6
-#define ADunbuff2_PORT GPIOC
-
-#define ADunbuff3_WIDTH 3
-#define ADunbuff3_SHIFT 10
-#define ADunbuff3_PORT GPIOC
-
-#define DB_OFS 0
-#define DB_WIDTH 8
-#define DB_SHIFT 8
-#define DB_PORT GPIOB
-
-
#define Z80_O_MREQ SBIT(P_MREQ, 4)
#define Z80_O_RD SBIT(P_RD, 3)
#define Z80_O_WR SBIT(P_WR, 2)
#define Z80_O_BUSREQ SBIT(P_BUSREQ, 7)
//#define Z80_O_NMI SBIT(P_NMI, )
#define Z80_O_RST SBIT(P_RST, 5)
-#define Z80_I_BUSACK SBIT(P_BUSACK, 6)
+#define Z80_I_BUSACK SBIT(PIN_BUSACK, 6)
//#define Z80_I_HALT SBIT(P_HALT, )
+
void z80_busreq(level_t level)
{
Z80_O_BUSREQ = level;
@@ -210,25 +178,31 @@ typedef union {
/*--------------------------------------------------------------------------*/
-
-/*
- * A0..A6, A8..A13 are buffered. No need to disable.
- * A7, A14..A18: set to input.
- */
-
-static void z80_setup_adrbus_tristate(void)
+static void z80_setup_addrbus_tristate(void)
{
+ /* /MREQ, /RD, /WR: Input, no pullup */
+ DDR_MREQ &= ~(_BV(MREQ) | _BV(RD) | _BV(WR));
+ Z80_O_MREQ = 0;
+ Z80_O_RD = 0;
+ Z80_O_WR = 0;
+
P_ADL = 0;
DDR_ADL = 0;
P_ADH = 0;
DDR_ADH = 0;
- PIN_ADB = P_ADB & MASK(ADB_WIDTH) << ADB_SHIFT;
+ PIN_ADB = P_ADB & ~(MASK(ADB_WIDTH) << ADB_SHIFT);
DDR_ADB = DDR_ADB & ~(MASK(ADB_WIDTH) << ADB_SHIFT);
}
-static void z80_setup_adrbus_active(void)
+static void z80_setup_addrbus_active(void)
{
+ /* /MREQ, /RD, /WR: Output and high */
+ Z80_O_MREQ = 1;
+ Z80_O_RD = 1;
+ Z80_O_WR = 1;
+ DDR_MREQ |= _BV(MREQ) | _BV(RD) | _BV(WR);
+
DDR_ADL = 0xff;
DDR_ADH = 0xff;
DDR_ADB = DDR_ADB | (MASK(ADB_WIDTH) << ADB_SHIFT);
@@ -247,66 +221,66 @@ static void z80_setup_dbus_out(void)
DDR_DB = 0xff;
}
-static
-void z80_setaddress(uint32_t addr)
-{
- addr_t x; x.l = addr;
-
- P_ADL = x.b[0];
- P_ADH = x.b[1];
- PIN_ADB = ((x.b[2] << ADB_SHIFT) ^ P_ADB) & MASK(ADB_WIDTH) << ADB_SHIFT ;
-}
-
void z80_setup_bus(void)
{
+ /* /ZRESET: Output and low */
Z80_O_RST = 0;
DDR_RST |= _BV(RST);
+ /* /BUSREQ: Output and high */
Z80_O_BUSREQ = 1;
DDR_BUSREQ |= _BV(BUSREQ);
-// Z80_O_NMI = 1;
-// DDR_NMI |= _BV(NMI);
-
- Z80_O_MREQ = 1;
- Z80_O_RD = 1;
- Z80_O_WR = 1;
- DDR_MREQ |= _BV(MREQ) | _BV(RD) | _BV(WR);
-
+ /* /BUSACK: Input, no pullup */
DDR_BUSACK &= ~_BV(BUSACK);
P_BUSACK &= ~_BV(BUSACK);
+ /* /IOCS1: Input, no pullup */
DDR_IOCS1 &= ~_BV(IOCS1);
P_IOCS1 &= ~_BV(IOCS1);
- //Z80_O_BUSREQ = 0;
- //while(Z80_I_BUSACK == 1);
-
- z80_setup_adrbus_tristate();
+ z80_setup_addrbus_tristate();
z80_setup_dbus_in();
}
+/*--------------------------------------------------------------------------*/
+
void z80_request_bus(void)
{
Z80_O_BUSREQ = 0;
while(Z80_I_BUSACK == 1);
- z80_setup_adrbus_active();
+ z80_setup_addrbus_active();
}
void z80_release_bus(void)
{
z80_setup_dbus_in();
- z80_setup_adrbus_tristate();
+ z80_setup_addrbus_tristate();
Z80_O_BUSREQ = 1;
- while(Z80_I_BUSACK == 0);
+ //while(Z80_I_BUSACK == 0);
+}
+
+/*--------------------------------------------------------------------------*/
+
+static
+//inline __attribute__ ((always_inline))
+void z80_setaddress(uint32_t addr)
+{
+ addr_t x; x.l = addr;
+
+ P_ADL = x.b[0];
+ P_ADH = x.b[1];
+ PIN_ADB = ((x.b[2] << ADB_SHIFT) ^ P_ADB) & MASK(ADB_WIDTH) << ADB_SHIFT ;
}
void z80_write(uint32_t addr, uint8_t data)
{
z80_setaddress(addr);
Z80_O_MREQ = 0;
- P_DB = data;
z80_setup_dbus_out();
+ P_DB = data;
+ P_DB = data;
+ Z80_O_WR = 0;
Z80_O_WR = 0;
Z80_O_WR = 1;
Z80_O_MREQ = 1;
@@ -321,6 +295,7 @@ uint8_t z80_read(uint32_t addr)
z80_setup_dbus_in();
Z80_O_RD = 0;
Z80_O_RD = 0;
+ Z80_O_RD = 0;
data = PIN_DB;
Z80_O_RD = 1;
Z80_O_MREQ = 1;
@@ -336,13 +311,15 @@ void z80_memset(uint32_t addr, uint8_t data, uint32_t length)
while(length--) {
z80_setaddress(addr++);
P_DB = data;
+ P_DB = data;
+ Z80_O_WR = 0;
Z80_O_WR = 0;
Z80_O_WR = 1;
}
Z80_O_MREQ = 1;
}
-void z80_write_block(uint8_t *src, uint32_t dest, uint32_t length)
+void z80_write_block(const __flash uint8_t *src, uint32_t dest, uint32_t length)
{
uint8_t data;
@@ -352,6 +329,8 @@ void z80_write_block(uint8_t *src, uint32_t dest, uint32_t length)
z80_setaddress(dest++);
data = *src++;
P_DB = data;
+ P_DB = data;
+ Z80_O_WR = 0;
Z80_O_WR = 0;
Z80_O_WR = 1;
}
@@ -547,6 +526,7 @@ int z80_msg_fifo_getc(void)
{
int c = -1;
+#if 0
if (msg_fifo.count != (NELEMS(msg_fifo.buf) /*- DMA1_CNDTR4 */ )) {
c = msg_fifo.buf[msg_fifo.count];
if (++msg_fifo.count == NELEMS(msg_fifo.buf))
@@ -558,6 +538,7 @@ int z80_msg_fifo_getc(void)
z80_release_bus();
}
}
+#endif
return c;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-01 17:10:48 +0000