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mac: clean up LATCH code
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@jeffpiep
jeffpiep committed Oct 21, 2023
1 parent 7c4964d commit 2602a96
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Showing 2 changed files with 52 additions and 78 deletions.
129 changes: 51 additions & 78 deletions pico/mac/commands.c
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Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,7 @@
#include "latch.pio.h"
#include "mux.pio.h"

#include "dcd_latch.pio.h"
// #include "dcd_latch.pio.h"
#include "dcd_commands.pio.h"
#include "dcd_mux.pio.h"
#include "dcd_read.pio.h"
Expand Down Expand Up @@ -173,53 +173,30 @@ uint16_t latch;
uint8_t dcd_latch;

uint16_t get_latch() { return latch; }
uint8_t dcd_get_latch() { return dcd_latch; }
uint16_t dcd_get_latch() { return ((dcd_latch << 8) + dcd_latch); }

uint16_t set_latch(enum latch_bits s)
{
latch |= (1u << s);
return latch;
};
void set_latch(enum latch_bits s) { latch |= (1u << s); }

uint8_t dcd_set_latch(uint8_t s)
{
dcd_latch |= (1u << s);
return dcd_latch;
}
void dcd_set_latch(uint8_t s) { dcd_latch |= (1u << s); }

uint16_t clr_latch(enum latch_bits c)
{
latch &= ~(1u << c);
return latch;
};
void clr_latch(enum latch_bits c) { latch &= ~(1u << c); }

uint8_t dcd_clr_latch(uint8_t c)
{
dcd_latch &= ~(1u << c);
return dcd_latch;
};
void dcd_clr_latch(uint8_t c) { dcd_latch &= ~(1u << c); }

uint8_t dcd_assert_hshk()
{
dcd_clr_latch(2);
dcd_clr_latch(3);
void dcd_assert_hshk()
{ // State CA2 CA1 CA0 HOST HOFF RESET RD Function
dcd_clr_latch(2); // 2 Low High Low Low Low Low !HSHK
dcd_clr_latch(3); // 3 Low High High High Low Low !HSHK
pio_sm_put_blocking(pio_dcd, SM_DCD_LATCH, dcd_get_latch()); // send the register word to the PIO
return dcd_latch;
}

uint8_t dcd_deassert_hshk()
{
dcd_set_latch(2);
dcd_set_latch(3);
void dcd_deassert_hshk()
{ // State CA2 CA1 CA0 HOST HOFF RESET RD Function
dcd_set_latch(2); // 2 Low High Low Low Low Low !HSHK
dcd_set_latch(3); // 3 Low High High High Low Low !HSHK
pio_sm_put_blocking(pio_dcd, SM_DCD_LATCH, dcd_get_latch()); // send the register word to the PIO
return dcd_latch;
}

// bool latch_val(enum latch_bits b)
// {
// return (latch & (1u << b));
// }

void preset_latch()
{
latch =0;
Expand All @@ -240,7 +217,16 @@ void preset_latch()

void dcd_preset_latch()
{
dcd_latch = 0b11011100; // DCD signature HHLx + no handshake HHxx
dcd_latch = 0;
// State CA2 CA1 CA0 HOST HOFF RESET RD Function
dcd_clr_latch(0); // 0 Low Low Low High High Low Data
dcd_clr_latch(1); // 1 Low Low High High Low Low Data
dcd_set_latch(2); // 2 Low High Low Low Low Low !HSHK
dcd_set_latch(3); // 3 Low High High High Low Low !HSHK
dcd_set_latch(4); // 4 High Low Low Low Low High --
dcd_clr_latch(5); // 5 High Low High Low Low Low Drive Low
dcd_set_latch(6); // 6 High High Low Low Low Low Drive High
dcd_set_latch(7); // 7 High High High Low Low Low Drive High
}

void set_tach_freq(char c)
Expand All @@ -257,7 +243,6 @@ void set_tach_freq(char c)
}
}

void loop();
void dcd_loop();
void floppy_loop();

Expand Down Expand Up @@ -294,8 +279,8 @@ void setup()

dcd_preset_latch();

offset = pio_add_program(pio_dcd, &dcd_latch_program);
printf("\nLoaded DCD latch program at %d\n", offset);
offset = pio_add_program(pio_dcd, &latch_program);
printf("\nLoaded latch program at %d\n", offset);
pio_dcd_latch(pio_dcd, SM_DCD_LATCH, offset, MCI_CA0, LATCH_OUT);
pio_sm_put_blocking(pio_dcd, SM_DCD_LATCH, dcd_get_latch()); // send the register word to the PIO

Expand Down Expand Up @@ -485,18 +470,6 @@ void dcd_process(uint8_t nrx, uint8_t ntx);

void dcd_loop()
{
// latest thoughts:
// this loop handshakes and receives the DCD command and fires off the command handler
// todo: make dcd_mux.pio push the DCD volume # (or floppy state) to the input FIFO.

// thoughts:
// this is done by a SM: during boot sequence, need to look for STRB to deal with daisy chained DCD and floppy
// if only one HD20, then after first STRB, READ should go hi-z.
// then maybe we get a reset? the Reset should allow READ to go output when ENABLED
//
// need a state variable to track changes in the "command" phase settings
//
//
if (!pio_sm_is_rx_fifo_empty(pio_dcd, SM_DCD_MUX))
{
active_disk_number = num_dcd_drives + 'A' - pio_sm_get_blocking(pio_dcd, SM_DCD_MUX);
Expand Down Expand Up @@ -882,7 +855,7 @@ void dcd_status(uint8_t ntx)

void dcd_id(uint8_t ntx)
{

// to do - move generation of the ID response packet to the ESP32 so the capacity can be generated
/*
DCD Device:
Offset Value Sample Value from HD20
Expand Down Expand Up @@ -927,26 +900,26 @@ void dcd_id(uint8_t ntx)
// assert(false);
}

void dcd_unknown(uint8_t ntx)
{
/*
DCD Device:
Offset Value Sample Value from HD20
0 0x83
1 0x00
2-5 Status
6 checksum
*/
printf("sending0x22 ");
memset(payload, 0, sizeof(payload));
payload[0] = 0x80 | 0x22;
compute_checksum(6);
assert(ntx==1);

send_packet(ntx);
// simulate_packet(ntx);
// assert(false);
}
// void dcd_unknown(uint8_t ntx)
// {
// /*
// DCD Device:
// Offset Value Sample Value from HD20
// 0 0x83
// 1 0x00
// 2-5 Status
// 6 checksum
// */
// printf("sending0x22 ");
// memset(payload, 0, sizeof(payload));
// payload[0] = 0x80 | 0x22;
// compute_checksum(6);
// assert(ntx==1);

// send_packet(ntx);
// // simulate_packet(ntx);
// // assert(false);
// }

void dcd_format(uint8_t ntx)
{
Expand Down Expand Up @@ -1096,9 +1069,9 @@ void dcd_process(uint8_t nrx, uint8_t ntx)
case 0x1a:
dcd_verify(ntx);
break;
case 0x22:
dcd_unknown(ntx);
break;
// case 0x22:
// dcd_unknown(ntx);
// break;
case 0x41:
// cont to write sectors
dcd_write(ntx, true, false);
Expand Down Expand Up @@ -1138,7 +1111,7 @@ void pio_mux(PIO pio, uint sm, uint offset, uint in_pin, uint mux_pin)

void pio_dcd_latch(PIO pio, uint sm, uint offset, uint in_pin, uint out_pin)
{
dcd_latch_program_init(pio, sm, offset, in_pin, out_pin);
latch_program_init(pio, sm, offset, in_pin, out_pin);
pio_sm_set_enabled(pio, sm, true);
}

Expand Down
1 change: 1 addition & 0 deletions pico/mac/latch.pio
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@
;
; Vintage Macintosh Microfloppy Controller Interface
; Reads the drive phases and output a latch bit
; for DCD, the 8-bit latch register should be copied into upper and lower bytes of the value pulled by the SM
;

.define ENABLE 7
Expand Down

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