--- /dev/null
+/**
+ * \brief Size-optimized code for TPI
+ * \file tpi.s
+ * \author S³awomir Fra\9c
+ */
+#include <avr/io.h>
+#include "tpi_defs.h"
+
+
+#define TPI_CLK_PORT PORTB
+#define TPI_CLK_DDR DDRB
+#define TPI_CLK_BIT 5
+#define TPI_DATAOUT_PORT PORTB
+#define TPI_DATAOUT_DDR DDRB
+#define TPI_DATAOUT_BIT 3
+#ifdef TPI_WITH_OPTO
+# define TPI_DATAIN_PIN PINB
+# define TPI_DATAIN_DDR DDRB
+# define TPI_DATAIN_BIT 4
+#else
+# define TPI_DATAIN_PIN PINB
+# define TPI_DATAIN_BIT 3
+#endif
+
+.comm tpi_dly_cnt, 2
+
+
+/**
+ * TPI init
+ */
+.global tpi_init
+tpi_init:
+ /* CLK <= out */
+ sbi _SFR_IO_ADDR(TPI_CLK_DDR), TPI_CLK_BIT
+#ifdef TPI_WITH_OPTO
+ /* DATAIN <= pull-up */
+ cbi _SFR_IO_ADDR(TPI_DATAIN_DDR), TPI_DATAIN_BIT
+ sbi _SFR_IO_ADDR(TPI_DATAIN_PORT), TPI_DATAIN_BIT
+ /* DATAOUT <= high */
+ sbi _SFR_IO_ADDR(TPI_DATAOUT_DDR), TPI_DATAOUT_BIT
+ sbi _SFR_IO_ADDR(TPI_DATAOUT_PORT), TPI_DATAOUT_BIT
+#else
+ /* DATA <= pull-up */
+ cbi _SFR_IO_ADDR(TPI_DATAOUT_DDR), TPI_DATAOUT_BIT
+ sbi _SFR_IO_ADDR(TPI_DATAOUT_PORT), TPI_DATAOUT_BIT
+#endif
+
+ /* 32 bits */
+ ldi r21, 32
+1:
+ rcall tpi_bit_h
+ dec r21
+ brne 1b
+
+ ret
+
+
+/**
+ * Update PR
+ * in: r25:r24 <= PR
+ * lost: r18-r21,r24,r30-r31
+ */
+tpi_pr_update:
+ movw r20, r24
+ ldi r24, TPI_OP_SSTPR(0)
+ rcall tpi_send_byte
+ mov r24, r20
+ rcall tpi_send_byte
+ ldi r24, TPI_OP_SSTPR(1)
+ rcall tpi_send_byte
+ mov r24, r21
+// rjmp tpi_send_byte
+
+
+/**
+ * Send one byte
+ * in: r24 <= byte
+ * lost: r18-r19,r30-r31
+ */
+.global tpi_send_byte
+tpi_send_byte:
+ /* start bit */
+ rcall tpi_bit_l
+ /* 8 data bits */
+ ldi r18, 8
+ ldi r19, 0
+1:
+ // parity
+ eor r19, r24
+ // get bit, shift
+ bst r24, 0
+ lsr r24
+ // send
+ rcall tpi_bit
+ dec r18
+ brne 1b
+ /* parity bit */
+ bst r19, 0
+ rcall tpi_bit
+ /* 2 stop bits */
+ rcall tpi_bit_h
+// rjmp tpi_bit_h
+
+
+/**
+ * Exchange of one bit
+ * in: T <= bit_in
+ * out: T => bit_out
+ * lost: r30-r31
+ */
+tpi_bit_h:
+ set
+tpi_bit:
+ /* TPIDATA = T */
+#ifdef TPI_WITH_OPTO
+ // DATAOUT = high (opto should allow TPIDATA to be pulled low by external device)
+ // if(T == 0)
+ // DATAOUT = low
+ sbi _SFR_IO_ADDR(TPI_DATAOUT_PORT), TPI_DATAOUT_BIT
+ brts 1f
+tpi_bit_l:
+ cbi _SFR_IO_ADDR(TPI_DATAOUT_PORT), TPI_DATAOUT_BIT
+1:
+#else
+ // DATAOUT = pull-up
+ // if(T == 0)
+ // DATAOUT = low
+ cbi _SFR_IO_ADDR(TPI_DATAOUT_DDR), TPI_DATAOUT_BIT
+ sbi _SFR_IO_ADDR(TPI_DATAOUT_PORT), TPI_DATAOUT_BIT
+ brts 1f
+tpi_bit_l:
+ cbi _SFR_IO_ADDR(TPI_DATAOUT_PORT), TPI_DATAOUT_BIT
+ sbi _SFR_IO_ADDR(TPI_DATAOUT_DDR), TPI_DATAOUT_BIT
+1:
+#endif
+ /* delay(); */
+ lds r30, tpi_dly_cnt
+ lds r31, tpi_dly_cnt+1
+1:
+ sbiw r30, 1
+ brsh 1b
+ /* TPICLK = 1 */
+ sbi _SFR_IO_ADDR(TPI_CLK_PORT), TPI_CLK_BIT
+ /* T = TPIDATA */
+ in r30, _SFR_IO_ADDR(TPI_DATAIN_PIN)
+ bst r30, TPI_DATAIN_BIT
+ /* delay(); */
+ lds r30, tpi_dly_cnt
+ lds r31, tpi_dly_cnt+1
+1:
+ sbiw r30, 1
+ brsh 1b
+
+ /* TPICLK = 0 */
+ cbi _SFR_IO_ADDR(TPI_CLK_PORT), TPI_CLK_BIT
+ ret
+
+
+/**
+ * Receive one byte
+ * out: r24 => byte
+ * lost: r18-r19,r30-r31
+ */
+.global tpi_recv_byte
+tpi_recv_byte:
+ /* waitfor(start_bit, 192); */
+ ldi r18, 192
+1:
+ rcall tpi_bit_h
+ brtc .tpi_recv_found_start
+ dec r18
+ brne 1b
+ /* no start bit: set return value */
+.tpi_break_ret0:
+ ldi r24, 0
+ /* send 2 breaks (24++ bits) */
+ ldi r18, 26
+1:
+ rcall tpi_bit_l
+ dec r18
+ brne 1b
+ /* send hi */
+ rjmp tpi_bit_h
+
+// ----
+.tpi_recv_found_start:
+ /* recv 8bits(+calc.parity) */
+ ldi r18, 8
+ ldi r19, 0
+1:
+ rcall tpi_bit_h
+ lsr r24
+ bld r24, 7
+ eor r19, r24
+ dec r18
+ brne 1b
+ /* recv parity */
+ rcall tpi_bit_h
+ bld r18, 7
+ eor r19, r18
+ brmi .tpi_break_ret0
+ /* recv stop bits */
+ rcall tpi_bit_h
+ rjmp tpi_bit_h
+
+
+/**
+ * Read Block
+ */
+.global tpi_read_block
+tpi_read_block:
+ // X <= dptr
+ movw XL, r22
+ // r23 <= len
+ mov r23, r20
+ /* set PR */
+ rcall tpi_pr_update
+ /* read data */
+.tpi_read_loop:
+ ldi r24, TPI_OP_SLD_INC
+ rcall tpi_send_byte
+ rcall tpi_recv_byte
+ st X+, r24
+ dec r23
+ brne .tpi_read_loop
+ ret
+
+
+/**
+ * Write block
+ */
+.global tpi_write_block
+tpi_write_block:
+ // X <= sptr
+ movw XL, r22
+ // r23 <= len
+ mov r23, r20
+ /* set PR */
+ rcall tpi_pr_update
+ /* write data */
+.tpi_write_loop:
+ ldi r24, TPI_OP_SOUT(NVMCMD)
+ rcall tpi_send_byte
+ ldi r24, NVMCMD_WORD_WRITE
+ rcall tpi_send_byte
+ ldi r24, TPI_OP_SST_INC
+ rcall tpi_send_byte
+ ld r24, X+
+ rcall tpi_send_byte
+.tpi_nvmbsy_wait:
+ ldi r24, TPI_OP_SIN(NVMCSR)
+ rcall tpi_send_byte
+ rcall tpi_recv_byte
+ andi r24, NVMCSR_BSY
+ brne .tpi_nvmbsy_wait
+ dec r23
+ brne .tpi_write_loop
+ ret
projects / pub / USBasp.git / blobdiff