diff options
Diffstat (limited to 'stm32/z80-if.c')
| -rw-r--r-- | stm32/z80-if.c | 731 |
1 files changed, 731 insertions, 0 deletions
diff --git a/stm32/z80-if.c b/stm32/z80-if.c new file mode 100644 index 0000000..171fea9 --- /dev/null +++ b/stm32/z80-if.c @@ -0,0 +1,731 @@ +/** + * + * Pin assignments + * + * | Z180-Sig | STM32-Port |Buffer | Dir | Special Function | + * +------------+---------------+-------+-------+-----------------------+ + * | A0 | A 1 | P | O | | + * | A1 | A 2 | P | O | | + * | A2 | A 3 | P | O | | + * | A3 | A 4 | P | O | | + * | A4 | A 5 | P | O | | + * | A5 | A 6 | P | O | | + * | A6 | A 7 | P | O | | + * | A7 | A 8 | | O | | + * | A8 | C 0 | P | O | | + * | A9 | C 1 | P | O | | + * | A10 | C 2 | P | O | | + * | A11 | C 3 | P | O | | + * | A12 | C 4 | P | O | | + * | A13 | C 5 | P | O | | + * | A14 | C 6 | | O | | + * | A15 | C 7 | | O | | + * | A16 | C 10 | | O | | + * | A17 | C 11 | | O | | + * | A18 | C 12 | | O | | + * | D0 | B 8 | | I/O | | + * | D1 | B 9 | | I/O | | + * | D2 | B 10 | | I/O | | + * | D3 | B 11 | | I/O | | + * | D4 | B 12 | | I/O | | + * | D5 | B 13 | | I/O | | + * | D6 | B 14 | | I/O | | + * | D7 | B 15 | | I/O | | + * | ME | C 13 | P | O | | + * | RD | B 0 | P | O | | + * | WR | B 1 | P | O | | + * | BUSREQ | D 2 | | O | | + * | IOCS1 | A 11 | | I | TIM1_CH4 | + * | BUSACK | A 12 | | I | | + * | HALT | A 12 | | I | | + * | NMI | B 7 | | O | | + * | RST | B 6 | | O | TIM16_CH1N | + * | | | | | | + * | | A 9 | | | af1 USART1_TX | + * | | A 10 | | | af1 USART1_RX | + * | | A 15 | | JTDI | remap SPI1_NSS' | + * | | B 3 | | JTDO | remap SPI1_SCK' | + * | | B 4 | |NJTRST | remap SPI1_MISO' | + * | | B 5 | | | remap SPI1_MOSI' | + * | | C 14 | | | af1 OSC32 | + * | | C 15 | | | af1 OSC32 | + + +AFIO_MAPR2 = +AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_ON (frees +AFIO_MAPR_SPI1_REMAP + + */ + +/** + * + * Pin assignments + * + * | Z180-Sig | STM32-Port | Buffer | Dir |Special Function | + * | -------- | ---------- | ------ | --- | --------------- | + * | A0 |A 1 |P |O | | + * | A1 |A 2 |P |O | | + * | A2 |A 3 |P |O | | + * | A3 |A 4 |P |O | | + * | A4 |A 5 |P |O | | + * | A5 |A 6 |P |O | | + * | A6 |A 7 |P |O | | + * | A7 |A 8 | |O | | + * | A8 |C 0 |P |O | | + * | A9 |C 1 |P |O | | + * | A10 |C 2 |P |O | | + * | A11 |C 3 |P |O | | + * | A12 |C 4 |P |O | | + * | A13 |C 5 |P |O | | + * | A14 |C 6 | |O | | + * | A15 |C 7 | |O | | + * | A16 |C 10 | |O | | + * | A17 |C 11 | |O | | + * | A18 |C 12 | |O | | + * | D0 |B 8 | |I/O | | + * | D1 |B 9 | |I/O | | + * | D2 |B 10 | |I/O | | + * | D3 |B 11 | |I/O | | + * | D4 |B 12 | |I/O | | + * | D5 |B 13 | |I/O | | + * | D6 |B 14 | |I/O | | + * | D7 |B 15 | |I/O | | + * | ME |C 13 |P |O | | + * | RD |B 0 |P |O | | + * | WR |B 1 |P |O | | + * | BUSREQ |D 2 | |O | | + * | IOCS1 |A 11 | |I |TIM1_CH4 | + * | BUSACK |A 12 | |I | | + * | HALT |A 12 | |I | | + * | NMI |B 7 | |O | | + * | RST |B 6 | |O |TIM16_CH1N | + * | | | | | | + * | |A 9 | | |af1 USART1_TX | + * | |A 10 | | |af1 USART1_RX | + * | |A 15 | |JTDI | remap SPI1_NSS' | + * | |B 3 | |JTDO |remap SPI1_SCK' | + * | |B 4 | |NJTRST |remap SPI1_MISO' | + * | |B 5 | | |remap SPI1_MOSI' | + * | |C 14 | | |af1 OSC32 | + * | |C 15 | | |af1 OSC32 | + + +AFIO_MAPR2 = +AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_ON (frees +AFIO_MAPR_SPI1_REMAP + + */ + +#include <stdio.h> + + +#include <libopencm3/stm32/gpio.h> +#include <libopencm3/stm32/rcc.h> +#include <libopencm3/stm32/timer.h> +#include <libopencm3/stm32/dma.h> +#include "debug.h" +#include "z80-if.h" + + +/* Number of array elements */ +#define NELEMS(x) (sizeof x/sizeof *x) + +#define ODR 0x0c +#define IDR 0x08 + +#define CONCAT(x,y) x ## y +#define EVALUATOR(x,y) CONCAT(x,y) + +#define GPIO_(X) CONCAT(GPIO, X) + + + + +#define P_ME GPIOC +#define ME 13 +#define P_RD GPIOB +#define RD 0 +#define P_WR GPIOB +#define WR 1 +#define P_BUSREQ GPIOD +#define BUSREQ 2 +#define P_BUSACK GPIOA +#define BUSACK 12 +//#define P_HALT GPIOA +//#define HALT 12 +#define P_IOCS1 GPIOA +#define IOCS1 11 +#define P_NMI GPIOB +#define NMI 7 +#define P_RST GPIOB +#define RST 6 + +#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 GPIO_ME GPIO_(ME) +#define GPIO_RD GPIO_(RD) +#define GPIO_WR GPIO_(WR) +#define GPIO_BUSREQ GPIO_(BUSREQ) +#define GPIO_BUSACK GPIO_(BUSACK) +//#define GPIO_HALT GPIO_(HALT) +#define GPIO_IOCS1 GPIO_(IOCS1) +#define GPIO_NMI GPIO_(NMI) +#define GPIO_RST GPIO_(RST) + +#define Z80_O_ME BBIO_PERIPH(P_ME+ODR, ME) +#define Z80_O_RD BBIO_PERIPH(P_RD+ODR, RD) +#define Z80_O_WR BBIO_PERIPH(P_WR+ODR, WR) +#define Z80_O_BUSREQ BBIO_PERIPH(P_BUSREQ+ODR, BUSREQ) +#define Z80_O_NMI BBIO_PERIPH(P_NMI+ODR, NMI) +#define Z80_O_RST BBIO_PERIPH(P_RST+ODR, RST) + +#define Z80_I_BUSACK BBIO_PERIPH(P_BUSACK+IDR, BUSACK) +//#define Z80_I_HALT BBIO_PERIPH(P_HALT+IDR, HALT) + + +#define MASK(n) ((1<<n)-1) + +#define IOFIELD_SET(src, ofs, width, shift) \ + ((((src>>ofs) & MASK(width)) << shift) | ((((~src>>ofs) & MASK(width)) << shift) << 16)) + +#define IOFIELD_GET(src, width, shift) \ + ((src>>shift) & MASK(width)) + +#define CNF_MODE_I_F (GPIO_CNF_INPUT_FLOAT<<2 |GPIO_MODE_INPUT) +#define CNF_MODE_O_PP (GPIO_CNF_OUTPUT_PUSHPULL<<2 | GPIO_MODE_OUTPUT_10_MHZ) + +#define DB_MODE_INPUT ( (CNF_MODE_I_F << (4 * 0)) \ + | (CNF_MODE_I_F << (4 * 1)) \ + | (CNF_MODE_I_F << (4 * 2)) \ + | (CNF_MODE_I_F << (4 * 3)) \ + | (CNF_MODE_I_F << (4 * 4)) \ + | (CNF_MODE_I_F << (4 * 5)) \ + | (CNF_MODE_I_F << (4 * 6)) \ + | (CNF_MODE_I_F << (4 * 7))) + +#define DB_MODE_OUTPUT ( (CNF_MODE_O_PP << (4 * 0)) \ + | (CNF_MODE_O_PP << (4 * 1)) \ + | (CNF_MODE_O_PP << (4 * 2)) \ + | (CNF_MODE_O_PP << (4 * 3)) \ + | (CNF_MODE_O_PP << (4 * 4)) \ + | (CNF_MODE_O_PP << (4 * 5)) \ + | (CNF_MODE_O_PP << (4 * 6)) \ + | (CNF_MODE_O_PP << (4 * 7))) + + +/*--------------------------------------------------------------------------*/ + +static void tim16_setup(void) +{ + RCC_APB2RSTR |= RCC_APB2RSTR_TIM16RST; + RCC_APB2RSTR &= ~RCC_APB2RSTR_TIM16RST; + + TIM16_BDTR = TIM_BDTR_MOE; + + TIM16_CCMR1 = 0 + | TIM_CCMR1_OC1M_FORCE_LOW + | TIM_CCMR1_CC1S_OUT; + + TIM16_CCER = TIM_CCER_CC1NE + | TIM_CCER_CC1NP; + + TIM16_ARR = 48; /* default */ + TIM16_CCR1 = 1; /* */ +} + +/*--------------------------------------------------------------------------*/ + +static void tim16_set(int mode) +{ + uint16_t cc_mode; + + cc_mode = TIM_CCMR1_CC1S_OUT; + + TIM16_CR1 = TIM_CR1_OPM; + + if (mode < 0) + cc_mode |= TIM_CCMR1_OC1M_FORCE_LOW; + else if (mode == 0) + cc_mode |= TIM_CCMR1_OC1M_FORCE_HIGH; + else { + TIM16_ARR = mode; + cc_mode |= TIM_CCMR1_OC1M_PWM2; + } + + TIM16_CCMR1 = cc_mode; + + if (mode > 0) + TIM16_CR1 |= TIM_CR1_CEN; +} + +/*--------------------------------------------------------------------------*/ + + + +/* + * A0..A6, A8..A13 are buffered. No need to disable. + * A7, A14..A18: set to input. + */ + +static void z80_setup_adrbus_tristate(void) +{ +#if 0 + gpio_set_mode(ADunbuff1_PORT, GPIO_MODE_INPUT, + GPIO_CNF_INPUT_FLOAT, MASK(ADunbuff1_WIDTH) << ADunbuff1_SHIFT); + gpio_set_mode(ADunbuff2_PORT, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, + (MASK(ADunbuff2_WIDTH) << ADunbuff2_SHIFT) | (MASK(ADunbuff3_WIDTH) << ADunbuff3_SHIFT)); +#else + GPIO_CRH(GPIOA) = (GPIO_CRH(GPIOA) & ~(0x0f << (4 * 0))) + | (CNF_MODE_I_F << (4 * 0)); + GPIO_CRL(GPIOC) = (GPIO_CRL(GPIOC) & ~((0x0f << (4 * 6)) | (0x0f << (4 * 7)))) + | ((CNF_MODE_I_F << (4 * 6)) | (CNF_MODE_I_F << (4 * 7))); + GPIO_CRH(GPIOC) = (GPIO_CRH(GPIOC) & ~((0x0f << (4*2)) | (0x0f << (4*3)) | (0x0f << (4*4)))) + | ((CNF_MODE_I_F << (4*2)) | (CNF_MODE_I_F << (4*3)) | (CNF_MODE_I_F << (4*4))); +#endif +} + + +static void z80_setup_adrbus_active(void) +{ +#if 0 + gpio_set_mode(ADunbuff1_PORT, GPIO_MODE_OUTPUT_10_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, MASK(ADunbuff1_WIDTH) << ADunbuff1_SHIFT); + gpio_set_mode(ADunbuff2_PORT, GPIO_MODE_OUTPUT_10_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, + (MASK(ADunbuff2_WIDTH) << ADunbuff2_SHIFT) | (MASK(ADunbuff3_WIDTH) << ADunbuff3_SHIFT)); +#else + GPIO_CRH(GPIOA) = (GPIO_CRH(GPIOA) & ~(0x0f << (4 * 0))) + | (CNF_MODE_O_PP << (4 * 0)); + GPIO_CRL(GPIOC) = (GPIO_CRL(GPIOC) & ~((0x0f << (4 * 6)) | (0x0f << (4 * 7)))) + | ((CNF_MODE_O_PP << (4 * 6)) | (CNF_MODE_O_PP << (4 * 7))); + GPIO_CRH(GPIOC) = (GPIO_CRH(GPIOC) & ~((0x0f << (4*2)) | (0x0f << (4*3)) | (0x0f << (4*4)))) + | ((CNF_MODE_O_PP << (4*2)) | (CNF_MODE_O_PP << (4*3)) | (CNF_MODE_O_PP << (4*4))); +#endif +} + + +static void z80_setup_dbus_in(void) +{ + GPIO_CRH(DB_PORT) = DB_MODE_INPUT; +} + +static void z80_setup_dbus_out(void) +{ + GPIO_CRH(DB_PORT) = DB_MODE_OUTPUT; +} + + +static void z80_setaddress(uint32_t addr) +{ + GPIO_BSRR(ADp1_PORT) = IOFIELD_SET(addr, ADp1_OFS, ADp1_WIDTH, ADp1_SHIFT); + GPIO_BSRR(ADp2_PORT) = IOFIELD_SET(addr, ADp2_OFS, ADp2_WIDTH, ADp2_SHIFT); + GPIO_BSRR(ADp3_PORT) = IOFIELD_SET(addr, ADp3_OFS, ADp3_WIDTH, ADp3_SHIFT); +} + +void z80_setup_bus(void) +{ + tim16_setup(); + + gpio_set_mode(P_RST, GPIO_MODE_OUTPUT_10_MHZ, + GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_RST); + Z80_O_BUSREQ = 1; + gpio_set_mode(P_BUSREQ, GPIO_MODE_OUTPUT_10_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO_BUSREQ); + Z80_O_NMI = 1; + gpio_set_mode(P_NMI, GPIO_MODE_OUTPUT_10_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO_NMI); + Z80_O_ME = 1; + Z80_O_RD = 1; + Z80_O_WR = 1; + gpio_set_mode(P_ME, GPIO_MODE_OUTPUT_2_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO_ME); + gpio_set_mode(P_RD, GPIO_MODE_OUTPUT_10_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO_RD | GPIO_WR); + + //Z80_O_BUSREQ = 0; + //while(Z80_I_BUSACK == 1); + + gpio_set_mode(ADp1_PORT, GPIO_MODE_OUTPUT_10_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, MASK(ADp1_WIDTH) << ADp1_SHIFT); + gpio_set_mode(ADp2_PORT, GPIO_MODE_OUTPUT_10_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, MASK(ADp2_WIDTH) << ADp2_SHIFT); + gpio_set_mode(ADp3_PORT, GPIO_MODE_OUTPUT_10_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, MASK(ADp3_WIDTH) << ADp3_SHIFT); + + z80_setup_dbus_in(); +} + +void z80_request_bus(void) +{ + Z80_O_BUSREQ = 0; + while(Z80_I_BUSACK == 1); + z80_setup_adrbus_active(); +} + +void z80_release_bus(void) +{ + z80_setup_dbus_in(); + z80_setup_adrbus_tristate(); + Z80_O_BUSREQ = 1; + while(Z80_I_BUSACK == 0); +} + +void z80_reset(level_t level) +{ + int x = level ? -1 : 0; + + tim16_set(x); + +// Z80_O_RST = level; +} + +void z80_reset_pulse(void) +{ + tim16_set(48); +} + +void z80_busreq(level_t level) +{ + Z80_O_BUSREQ = level; +} + +#if 0 +int z80_stat_halt(void) +{ + return Z80_I_HALT; +} +#endif + +void z80_write(uint32_t addr, uint8_t data) +{ + z80_setaddress(addr); + Z80_O_ME = 0; + GPIO_BSRR(DB_PORT) = IOFIELD_SET(data, DB_OFS, DB_WIDTH, DB_SHIFT); + z80_setup_dbus_out(); + Z80_O_WR = 0; + Z80_O_WR = 1; + Z80_O_ME = 1; +} + +uint8_t z80_read(uint32_t addr) +{ + uint8_t data; + + z80_setaddress(addr); + Z80_O_ME = 0; + z80_setup_dbus_in(); + Z80_O_RD = 0; + Z80_O_RD = 0; + data = IOFIELD_GET(GPIO_IDR(DB_PORT),DB_WIDTH, DB_SHIFT); + Z80_O_RD = 1; + Z80_O_ME = 1; + + return data; +} + + +void z80_memset(uint32_t addr, uint8_t data, int length) +{ + z80_setup_dbus_out(); + Z80_O_ME = 0; + while(length--) { + z80_setaddress(addr++); + GPIO_BSRR(DB_PORT) = IOFIELD_SET(data, DB_OFS, DB_WIDTH, DB_SHIFT); + Z80_O_WR = 0; + Z80_O_WR = 1; + } + Z80_O_ME = 1; +} + +void z80_write_block(uint8_t *src, uint32_t dest, uint32_t length) +{ + uint8_t data; + + z80_setup_dbus_out(); + Z80_O_ME = 0; + while(length--) { + z80_setaddress(dest++); + data = *src++; + GPIO_BSRR(DB_PORT) = IOFIELD_SET(data, DB_OFS, DB_WIDTH, DB_SHIFT); + Z80_O_WR = 0; + Z80_O_WR = 1; + } + Z80_O_ME = 1; +} + +/* + 0179' rx.bs_mask: ds 1 ; (buf_len - 1) + 017A' rx.in_idx: ds 1 ; + 017B' rx.out_idx: ds 1 ; + 017C' rx.buf: ds rx.buf_len ; + 018B' rx.buf_end equ $-1 ; last byte (start+len-1) + + 018C' tx.bs_mask: ds 1 ; (buf_len - 1) + 018D' tx.in_idx: ds 1 ; + 018E' tx.out_idx: ds 1 ; + 018F' tx.buf: ds tx.buf_len ; + 019E' tx.buf_end equ $-1 ; last byte +*/ + + +typedef struct __attribute__((packed)) { + uint8_t mask; + uint8_t in_idx; + uint8_t out_idx; + uint8_t buf[]; +} zfifo_t; + + + +#define FIFO_BUFSIZE_MASK -3 +#define FIFO_INDEX_IN -2 +#define FIFO_INDEX_OUT -1 + + +static struct { + uint32_t base; + uint8_t idx_out, + idx_in, + mask; + } fifo_dsc[NUM_FIFOS]; + + +void z80_memfifo_init(const fifo_t f, uint32_t adr) +{ + +DBG_P(2, "z80_memfifo_init: %i, %lx\n", f, adr); + + fifo_dsc[f].base = adr; + + z80_request_bus(); + + fifo_dsc[f].mask = z80_read(adr + FIFO_BUFSIZE_MASK); + fifo_dsc[f].idx_in = z80_read(adr + FIFO_INDEX_IN); + fifo_dsc[f].idx_out = z80_read(adr + FIFO_INDEX_OUT); + + z80_release_bus(); +} + + +int z80_memfifo_is_empty(const fifo_t f) +{ + int rc = 1; + + if (fifo_dsc[f].base != 0) { + + uint32_t adr = fifo_dsc[f].base + FIFO_INDEX_IN; + uint8_t idx; + + z80_request_bus(); + idx = z80_read(adr); + z80_release_bus(); + rc = idx == fifo_dsc[f].idx_out; + } + + return rc; +} + +int z80_memfifo_is_full(const fifo_t f) +{ + int rc = 1; + + if (fifo_dsc[f].base != 0) { + z80_request_bus(); + rc = ((fifo_dsc[f].idx_in + 1) & fifo_dsc[f].mask) + == z80_read(fifo_dsc[f].base+FIFO_INDEX_OUT); + z80_release_bus(); + } + return rc; +} + +uint8_t z80_memfifo_getc(const fifo_t f) +{ + uint8_t rc, idx; + + while (z80_memfifo_is_empty(f)) + ; + + z80_request_bus(); + idx = fifo_dsc[f].idx_out; + rc = z80_read(fifo_dsc[f].base+idx); + fifo_dsc[f].idx_out = ++idx & fifo_dsc[f].mask; + z80_write(fifo_dsc[f].base+FIFO_INDEX_OUT, fifo_dsc[f].idx_out); + z80_release_bus(); + + return rc; +} + + +void z80_memfifo_putc(fifo_t f, uint8_t val) +{ + int idx; + + while (z80_memfifo_is_full(f)) + ; + + z80_request_bus(); + idx = fifo_dsc[f].idx_in; + z80_write(fifo_dsc[f].base+idx, val); + fifo_dsc[f].idx_in = ++idx & fifo_dsc[f].mask; + z80_write(fifo_dsc[f].base+FIFO_INDEX_IN, fifo_dsc[f].idx_in); + z80_release_bus(); +} + +/*--------------------------------------------------------------------------*/ + +static struct { + uint32_t base; + //uint8_t idx_out, idx_in; + uint16_t count; + uint8_t buf[256]; + } msg_fifo; + +/*--------------------------------------------------------------------------*/ + +#if 0 + +static void tim1_setup(void) +{ + RCC_APB2RSTR |= RCC_APB2RSTR_TIM1RST; + RCC_APB2RSTR &= ~RCC_APB2RSTR_TIM1RST; + + TIM1_CR1 = 0; + + TIM1_SMCR = 0 + /* | TIM_SMCR_ETP */ + /* | TIM_SMCR_ETF_CK_INT_N_2 */ + | TIM_SMCR_TS_ETRF + | TIM_SMCR_SMS_OFF + ; + + TIM1_DIER = TIM_DIER_TDE; + + + TIM1_CCMR1 = 0 + | TIM_CCMR1_OC1M_FORCE_LOW + | TIM_CCMR1_CC1S_OUT; + + TIM1_SMCR |= TIM_SMCR_SMS_TM; +} + +#endif + +/*--------------------------------------------------------------------------*/ + +static void tim1_ch4_setup(void) +{ + /* Reset Timer 1 */ + RCC_APB2RSTR |= RCC_APB2RSTR_TIM1RST; + RCC_APB2RSTR &= ~RCC_APB2RSTR_TIM1RST; + + TIM1_CCMR2 = 0 + | TIM_CCMR2_CC4S_IN_TI2 + | TIM_CCMR2_IC4F_OFF + | TIM_CCMR2_IC4PSC_OFF; + + TIM1_CCER = 0 + /* | TIM_CCER_CC4P */ + | TIM_CCER_CC4E; + + /* Enable DMA for channel 4 */ + TIM1_DIER = TIM_DIER_CC4DE; +} + +/*--------------------------------------------------------------------------*/ + +static void dma1_ch4_setup(void) +{ + DMA1_CCR4 = + DMA_CCR_PL_VERY_HIGH + | DMA_CCR_MSIZE_8BIT + | DMA_CCR_PSIZE_8BIT + | DMA_CCR_MINC + | DMA_CCR_CIRC; + + DMA1_CMAR4 = (uint32_t) msg_fifo.buf; + +#if (DB_SHIFT == 0) || (DB_SHIFT == 8) + DMA1_CPAR4 = DB_PORT + IDR + DB_SHIFT/8; +#else + #error "Databus not byte aligned!" +#endif + + DMA1_CNDTR4 = NELEMS(msg_fifo.buf); +// msg_fifo.count = NELEMS(msg_fifo.buf); + msg_fifo.count = 0; + msg_fifo.base = 0; + + DMA1_CCR4 |= DMA_CCR_EN; +} + +/*--------------------------------------------------------------------------*/ + +void z80_setup_msg_fifo(void) +{ + gpio_set_mode(P_BUSACK, GPIO_MODE_INPUT, + GPIO_CNF_INPUT_FLOAT, GPIO_BUSACK | GPIO_IOCS1); + + tim1_ch4_setup(); + dma1_ch4_setup(); +} + + +void z80_init_msg_fifo(uint32_t addr) +{ + +DBG_P(1, "z80_init_msg_fifo: %lx\n", addr); + + z80_request_bus(); + z80_write(addr+FIFO_INDEX_OUT, z80_read(addr+FIFO_INDEX_IN)); + z80_release_bus(); + msg_fifo.base = addr; +} + + +int z80_msg_fifo_getc(void) +{ + int c = -1; + + 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)) + msg_fifo.count = 0; + + if (msg_fifo.base != 0) { + z80_request_bus(); + z80_write(msg_fifo.base+FIFO_INDEX_OUT, msg_fifo.count); + z80_release_bus(); + } + } + + return c; +} |