Datasheet

20
LTC1594/LTC1598
15948fb
TYPICAL APPLICATIONS N
U
LDA #$52 Configuration data for serial peripheral
control register (Interrupts disabled, output
enabled, master, Norm = 0, Ph = 0, Clk/16)
STA $0A Load configuration data into location $0A (SPCR)
LDA #$FF Configuration data for I/O ports
(all bits are set as outputs)
STA $04 Load configuration data into Port A DDR ($04)
STA $05 Load configuration data into Port B DDR ($05)
STA $06 Load configuration data into Port C DDR ($06)
LDA #$08 Put D
IN
word for LTC1598 into Accumulator
(CH0 with respect to GND)
STA $50 Load D
IN
word into memory location $50
START BSET 0,$02 Bit 0 Port C ($02) goes high (CS goes high)
LDA $50 Load D
IN
word at $50 into Accumulator
STA $0C Load D
IN
word into SPI data register ($0C) and
start clocking data
LOOP1 TST $0B Test status of SPIF bit in SPI status register ($0B)
MC68HC05 CODE
BPL LOOP1 Loop if not done with transfer to previous instruction
BCLR 0,$02 Bit 0 Port C ($02) goes low (CS goes low)
LDA $0C Load contents of SPI data register into Accumulator
STA $0C Start next SPI cycle
LOOP2 TST $0B Test status of SPIF
BPL LOOP2 Loop if not done
LDA $0C Load contents of SPI data register into Accumulator
STA $0C Start next SPI cycle
AND #$IF Clear 3 MSBs of first D
OUT
word
STA $00 Load Port A ($00) with MSBs
LOOP3 TST $0B Test status of SPIF
BPL LOOP3 Loop if not done
LDA $0C Load contents of SPI data register into Accumulator
AND #$FE Clear LSB of second D
OUT
word
STA $01 Load Port B ($01) with LSBs
JMP START Go back to start and repeat program
1594/98 TA04
D
OUT
FROM LTC1598 STORED IN MC68HC05 RAM
B1 B0
0
B2
B3
B5
B6 B4
0
0
LSB
MSB
#00
#01
0
B11 B10
B9
B8 B7
CLK
D
IN
CSMUX
CSADC
ANALOG
INPUTS
C0
SCK
MC68HC05
D
OUT
MOSI
LTC1598
BYTE 1
BYTE 2
MISO
Hardware and Software Interface to Motorola MC68HC05
Data Exchange Between LTC1598 and MC68HC05
CSMUX
= CSADC
= CS
CLK
D
OUT
MPU
RECEIVED
WORD
1594/98 TA03
B3B7 B6 B5 B4 B2 B1 B0 B1 B2B11 B10 B9 B8
D
IN
MPU
TRANSMIT
WORD
BYTE 3
BYTE 2
EN D20D1
X
D0
BYTE 1
X
X
X
X
X
X
X
000
X
X
X
XX
X
X
X
BYTE 3
BYTE 2
BYTE 1
B10
?
?
0
B11
B9
B7
B8
B6
B5
B3
B4 B2
B1
B1
B0
DON‘T CARE
D1D2
???
?????
DO
EN