diff options
| -rw-r--r-- | Makefile | 7 | ||||
| -rw-r--r-- | README.md | 2 | ||||
| -rw-r--r-- | main.c | 75 |
3 files changed, 48 insertions, 36 deletions
@@ -1,4 +1,3 @@ -MCU ?= attiny2313 AVRDUDE_PROGRAMMER ?= usbasp AVRCC ?= avr-gcc @@ -7,8 +6,8 @@ AVRNM ?= avr-nm AVROBJCOPY ?= avr-objcopy AVROBJDUMP ?= avr-objdump -CFLAGS += -mmcu=attiny2313 -DF_CPU=20000000UL -#CFLAGS += -gdwarf-2 -fverbose-asm -save-temps +CFLAGS += -mmcu=attiny2313a -DF_CPU=20000000UL +#CFLAGS += -gdwarf-2 -fverbose-asm CFLAGS += -I. -std=gnu99 -Os -Wall -Wextra -pedantic CFLAGS += -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums # r28 .. r31 hold the microsecond counters @@ -31,7 +30,7 @@ main.elf: main.c avr-size -d $@ program: main.hex main.eep - ${AVRFLASH} -p ${MCU} -c ${AVRDUDE_PROGRAMMER} ${AVRFLAGS} + ${AVRFLASH} -p attiny2313 -c ${AVRDUDE_PROGRAMMER} ${AVRFLAGS} secsize: main.elf ${AVROBJDUMP} -hw -j.text -j.bss -j.data main.elf @@ -1,6 +1,6 @@ # owi-slave -Implementation of an One Wire Interface slave device on an ATTiny 2313 without +Implementation of an One Wire Interface slave device on an ATTiny 2313A without external clock. This code is a work in progress. The Command readout is not working realibly. @@ -44,14 +44,16 @@ int main (void) { /* watchdog reset after ~4 seconds */ MCUSR &= ~_BV(WDRF); - WDTCSR = _BV(WDCE) | _BV(WDE); - WDTCSR = _BV(WDE) | _BV(WDP3); + WDTCR = _BV(WDCE) | _BV(WDE); + WDTCR = _BV(WDE) | _BV(WDP3); MCUCR = _BV(ISC10); GIMSK = _BV(INT1); ACSR |= _BV(ACD); + PRR = _BV(PRUSI) | _BV(PRUSART); + POS = 0; APOS = 0; DDRD = 0; @@ -138,14 +140,14 @@ ISR(INT1_vect) DDRD = _BV(PD3); - // 15us loop - r31 / r30 need not be preserved + // 15us loop - r31 / r28 need not be preserved asm volatile ("ldi r31, 0"); - asm volatile ("ldi r30, 15"); // Z = 120 + asm volatile ("ldi r28, 15"); // Z = 15 asm volatile ("wdr"); // <----- asm volatile ("wdr"); asm volatile ("wdr"); - asm volatile ("sbiw r30, 1"); - asm volatile ("cp r30, r1"); + asm volatile ("sbiw r28, 1"); + asm volatile ("cp r28, r1"); asm volatile ("brne .-12"); // -^ DDRD = 0; @@ -156,27 +158,38 @@ ISR(INT1_vect) POS <<= 1; } else { - APOS++; POS = 1; - if (APOS == 1) - BYTE = ~ADDR7; - else if (APOS == 2) - BYTE = ~ADDR6; - else if (APOS == 3) - BYTE = ~ADDR5; - else if (APOS == 4) - BYTE = ~ADDR4; - else if (APOS == 5) - BYTE = ~ADDR3; - else if (APOS == 6) - BYTE = ~ADDR2; - else if (APOS == 7) - BYTE = ~ADDR1; - - else if (APOS == 8) { - LASTCMD = 0; - POS = 0; - } + asm volatile ("in r28, 0x28"); // APOS + asm volatile ("inc r28"); // APOS++ + asm volatile ("cpi r28, 1"); + asm volatile ("brne .+2"); + asm volatile ("ldi r29, %0" : : "i" (~ADDR7)); + asm volatile ("cpi r28, 2"); + asm volatile ("brne .+2"); + asm volatile ("ldi r29, %0" : : "i" (~ADDR6)); + asm volatile ("cpi r28, 3"); + asm volatile ("brne .+2"); + asm volatile ("ldi r29, %0" : : "i" (~ADDR5)); + asm volatile ("cpi r28, 4"); + asm volatile ("brne .+2"); + asm volatile ("ldi r29, %0" : : "i" (~ADDR4)); + asm volatile ("cpi r28, 5"); + asm volatile ("brne .+2"); + asm volatile ("ldi r29, %0" : : "i" (~ADDR3)); + asm volatile ("cpi r28, 6"); + asm volatile ("brne .+2"); + asm volatile ("ldi r29, %0" : : "i" (~ADDR2)); + asm volatile ("cpi r28, 7"); + asm volatile ("brne .+2"); + asm volatile ("ldi r29, %0" : : "i" (~ADDR1)); + asm volatile ("out 0x1d, r29"); // BYTE + + asm volatile ("cpi r28, 8"); + asm volatile ("brne .+4"); + asm volatile ("out 0x3c, r1"); // LASTCMD - OC0B + asm volatile ("out 0x2a, r1"); // BUF - OC1A + + asm volatile ("out 0x28, r28"); // APOS } } else if (LASTCMD == 0xf0) { @@ -186,14 +199,14 @@ ISR(INT1_vect) //if (BYTE & POS) { DDRD = _BV(PD3); - // 15us loop - r31 / r30 need not be preserved - asm volatile ("ldi r31, 0"); - asm volatile ("ldi r30, 15"); // Z = 120 + // 15us loop - r29 / r28 need not be preserved + asm volatile ("ldi r29, 0"); + asm volatile ("ldi r28, 15"); // Z = 15 asm volatile ("wdr"); // <----- asm volatile ("wdr"); asm volatile ("wdr"); - asm volatile ("sbiw r30, 1"); - asm volatile ("cp r30, r1"); + asm volatile ("sbiw r28, 1"); + asm volatile ("cp r28, r1"); asm volatile ("brne .-12"); // -^ DDRD = 0; |