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ibmpc: busy wait only first time

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This is not tested well yet
This commit is contained in:
tmk 2021-07-05 12:11:38 +09:00
parent e9dab95909
commit 848cac6eb2
1 changed files with 14 additions and 5 deletions
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19
tmk_core/protocol/ibmpc.cpp
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@ -260,7 +260,7 @@ inline void IBMPC::isr(void)
// b7 b6 b5 b4 b3 b2 b1 b0 | 1 0 *1 0 0 0 0 0 XT_IBM-done ^2
// pr b7 b6 b5 b4 b3 b2 b1 | 1 0 *1 0 0 0 0 0 AT-midway[b0=1] ^2
// b7 b6 b5 b4 b3 b2 b1 b0 | 1 1 *1 0 0 0 0 0 XT_IBM-error-done
// x x x x x x x x | x 1 1 0 0 0 0 0 illegal
// x x x x x x x x | 0 1 *1 0 0 0 0 0 illegal
// st pr b7 b6 b5 b4 b3 b2 | b1 b0 0 *1 0 0 0 0 AT-done
// x x x x x x x x | x x 1 *1 0 0 0 0 illegal
// all other states than above illegal
@ -280,8 +280,12 @@ inline void IBMPC::isr(void)
{
uint8_t us = 100;
// wait for rising and falling edge of b7 of XT_IBM
while (!(IBMPC_CLOCK_PIN&(1<<clock_bit)) && us) { wait_us(1); us--; }
while ( IBMPC_CLOCK_PIN&(1<<clock_bit) && us) { wait_us(1); us--; }
if (!protocol) {
while (!(IBMPC_CLOCK_PIN&(1<<clock_bit)) && us) { wait_us(1); us--; }
while ( IBMPC_CLOCK_PIN&(1<<clock_bit) && us) { wait_us(1); us--; }
} else if (protocol == IBMPC_PROTOCOL_XT_CLONE) {
us = 0;
}
if (us) {
// XT_IBM-error: read start(0) as 1
@ -306,8 +310,12 @@ inline void IBMPC::isr(void)
{
uint8_t us = 100;
// wait for rising and falling edge of AT stop bit to discriminate between XT and AT
while (!(IBMPC_CLOCK_PIN&(1<<clock_bit)) && us) { wait_us(1); us--; }
while ( IBMPC_CLOCK_PIN&(1<<clock_bit) && us) { wait_us(1); us--; }
if (!protocol) {
while (!(IBMPC_CLOCK_PIN&(1<<clock_bit)) && us) { wait_us(1); us--; }
while ( IBMPC_CLOCK_PIN&(1<<clock_bit) && us) { wait_us(1); us--; }
} else if (protocol == IBMPC_PROTOCOL_XT_IBM) {
us = 0;
}
if (us) {
// found stop bit: AT-midway - process the stop bit in next ISR
@ -346,6 +354,7 @@ inline void IBMPC::isr(void)
case 0b11110000:
default: // xxxx_oooo(any 1 in low nibble)
// Illegal
protocol = 0;
isr_debug = isr_state;
error = IBMPC_ERR_ILLEGAL;
goto ERROR;