mirror of https://github.com/hsoft/collapseos.git
66 lines
1.6 KiB
C
66 lines
1.6 KiB
C
#include "sms_ports.h"
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void ports_init(Ports *ports)
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{
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ports->ctl = 0xff;
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ports->TRA = TRI_HIGHZ;
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ports->THA = TRI_HIGHZ;
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ports->TRB = TRI_HIGHZ;
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ports->THB = TRI_HIGHZ;
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}
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void ports_ctl_wr(Ports *ports, uint8_t val)
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{
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ports->ctl = val;
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ports->TRA = TRI_HIGHZ;
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ports->THA = TRI_HIGHZ;
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ports->TRB = TRI_HIGHZ;
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ports->THB = TRI_HIGHZ;
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if ((val & 0x01) == 0) {
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ports->TRA = ((val & 0x10) == 0) ? TRI_LOW : TRI_HIGH;
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}
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if ((val & 0x02) == 0) {
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ports->THA = ((val & 0x20) == 0) ? TRI_LOW : TRI_HIGH;
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}
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if ((val & 0x04) == 0) {
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ports->TRB = ((val & 0x40) == 0) ? TRI_LOW : TRI_HIGH;
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}
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if ((val & 0x08) == 0) {
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ports->THB = ((val & 0x80) == 0) ? TRI_LOW : TRI_HIGH;
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}
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}
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uint8_t ports_A_rd(Ports *ports)
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{
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// Bits 7:6 are port B's Down/Up
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// Bits 5:0 are port A's TR/TL/R/L/D/U
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uint8_t res = 0xff;
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if (ports->portA_rd != NULL) {
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res &= ports->portA_rd() | 0b11000000;
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}
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if (ports->portB_rd != NULL) {
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res &= (ports->portB_rd() << 6) | 0b00111111;
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}
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return res;
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}
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uint8_t ports_B_rd(Ports *ports)
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{
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// Bit 7: Port B's TH
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// Bit 6: Port A's TH
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// Bit 5: unused
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// Bit 4: unused (reset button)
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// Bits 3:0 are port B's TR/TL/R/L
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uint8_t res = 0xff;
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if (ports->portA_rd != NULL) {
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res &= ports->portA_rd() | 0b10111111;
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}
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if (ports->portB_rd != NULL) {
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uint8_t portb = ports->portB_rd();
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res &= (portb << 1) | 0b01111111; // TH
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res &= (portb >> 2) | 0b11110000; // TR/TL/R/L
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}
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return res;
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}
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