LTC1293 Datasheet, PDF (16/28 Pages) Linear Technology – Single Chip 12-Bit Data Acquisition System

LTC1293/LTC1294/LTC1296
APPLICATI S I FOR ATIO
MC68HC11 CODE
LABEL MNEMONIC OPERAND
LDAA
#$50
STAA
$1028
LDAA
#$1B
STAA
$1009
LDAA
#$10
STAA
$50
LDAA
#$E0
STAA
$51
LDAA
#$00
STAA
$52
LDX
#$1000
LOOP BCLR
$08,X,$01
LDAA
$50
STAA
$102A
LDAA
$1029
WAIT1 BPL
WAIT1
LDAA
$51
COMMENTS
CONFIGURATION DATA FOR SPCR
LOAD DATA INTO SPCR ($1028)
CONFIG. DATA FOR PORT D DDR
LOAD DATA INTO PORT D DDR
LOAD DIN WORD INTO ACC A
LOAD DIN DATA INTO $50
LOAD DIN WORD INTO ACC A
LOAD DIN DATA INTO $51
LOAD DUMMY DIN WORD INTO ACC A
LOAD DUMMY DIN DATA INTO $52
LOAD INDEX REGISTER X WITH $1000
D0 GOES LOW (CS GOES LOW)
LOAD DIN INTO ACC A FROM $50
LOAD DIN INTO SPI, START SCK
CHECK SPI STATUS REG
CHECK IF TRANSFER IS DONE
LOAD DIN INTO ACC A FROM $51
LABEL MNEMONIC OPERAND COMMENTS
STAA
$102A LOAD DIN INTO SPI, START SCK
WAIT2 LDAA
$1029 CHECK SPI STATUS REG
BPL
WAIT2 CHECK IF TRANSFER IS DONE
LDAA
$102A LOAD LTC1294 MSBs INTO ACC A
STAA
$62
STORE MSBs IN $62
LDAA
$52
LOAD DUMMY DIN INTO ACC A FROM
$52
STAA
$102A
LOAD DUMMY DIN INTO SPI, START
SCK
WAIT3 LDAA
$1029 CHECK SPI STATUS REG
BPL
WAIT3 CHECK IF TRANSFER IS DONE
BSET
$08,X,$01 D0 GOES HIGH (CS GOES HIGH)
LDAA
$102A LOAD LTC1294 LSBs IN ACC
STAA
$63
STORE LSBs IN $63
JMP
LOOP
START NEXT CONVERSION
Hardware and Software Interface to Intel 8051
PS BIT LATCHED
INTO LTC1294
CS
1
2
3
4
5
6
7
8
CLK
DATA
(D_IN/D_OUT)
SGL/ ODD/ SEL SEL
DIFF SIGN 1
0 UNI MSB PS
START
8051 P1.2 OUTPUT DATA
TO LTC1294
8051 P1.2 RECONFIGURED
AS INPUT AFTER THE 8TH RISING
CLK BEFORE THE 8TH FALLING CLK
B10 B8 B6 B4 B2 B0
B11 B9 B7 B5 B3 B1
LTC1294 SEND A/D RESULT
BACK TO 8051 P1.2
LTC1294 TAKES CONTROL OF DATA
LINE ON 8TH FALLING CLK
LTC1293 TD02
Hardware and Software Interface to Intel 8051
DOUT FROM LTC1294 STORED IN 8051 RAM
MSB
R2 B11 B10 B9 B8 B7 B6 B5 B4
LSB
R3 B3 B2 B1 B0
0
0
0
0
ANALOG
INPUTS
CS
P1.4
CLK
LTC1294
D_OUT
P1.3
8051
P1.2
D_IN
MUX ADDRESS
A/D RESULT
16
LTC1293 TD02a