Datasheet

11
LTC1291
1291fa
Timing Diagram for Interface to the MC68HC11
LABEL MNEMONIC OPERAND COMMENTS
LTC1291 AI07
D
OUT
FROM LTC1291 STORED IN MC68HC11 RAM
B2 B1
B0
B3
B4
B6
B7 B5
0
0
LSB
MSB
#62
#63
0
0 B11
B10
B9 B8
CLK
D
OUT
CS
ANALOG
INPUTS
D0
SCK
MC68HC11
D
IN
MISO
LTC1291
CH0
CH1
BYTE 1
BYTE 2
MOSI
Hardware and Software Interface to Motorola MC68HC11
MC68HC11 CODE
In this example the D
IN
word configures the input MUX for
a single-ended input to be applied to CH0. The conversion
result is output MSB-first.
CS
CLK
D
OUT
MPU
RECEIVED
WORD
LTC1291 AI06
SGL/
DIFF
START
MSBF PS
B3B7 B6 B5 B4 B2 B0B1B11 B10 B9 B8
D
IN
MPU
TRANSMIT
WORD
BYTE 3 (DUMMY)
BYTE 2
000
SGL/
DIFF
1
BYTE 1
X
ODD/
EVEN
MSBF
PS
X
X
X
X
000
X
X
X
XX
X
X
X
BYTE 3
BYTE 2
BYTE 1
B11
?
?
?
0
B10
B8
B9
B7
B6
B4
B5 B3
B2
B0
B1
DON'T CARE
ODD/
EVEN
???
?????
LABEL MNEMONIC OPERAND COMMENTS
LDAA #$50 CONFIGURATION DATA FOR SPCR
STAA $1028 LOAD DATA INTO SPCR ($1028)
LDAA #$1B CONFIG. DATA FOR PORT D DDR
STAA $1009 LOAD DATA INTO PORT D DDR
LDAA #$03 LOAD DIN WORD INTO ACC A
STAA $50 LOAD DIN DATA INTO $50
LDAA #$60 LOAD DIN WORD INTO ACC A
STAA $51 LOAD DIN DATA INTO $51
LDAA #$00 LOAD DUMMY DIN WORD INTO
ACC A
STAA $52 LOAD DUMMY DIN DATA INTO $52
LDX #$1000 LOAD INDEX REGISTER X WITH
$1000
LOOP BCLR $08,X,#$01 D0 GOES LOW (CS GOES LOW)
LDAA $50 LOAD DIN INTO ACC A FROM $50
STAA $102A LOAD DIN INTO SPI, START SCK
U
S
A
O
PP
L
IC
AT
I
WU
U
I FOR ATIO