Datasheet

AD7912/AD7922
Rev. 0 | Page 23 of 32
04351-0-031
SCLK
CS
DOUT
DON'T CARE DON'T CARE VALID DATA ADC2 VALID DATA ADC1 DON'T CAREDON'T CARE
NORMAL MODE
CONVERSION ON THE
TWO DEVICES
NORMAL MODE
CONVERSION ON THE
TWO DEVICES
CHANGE MODE
CS HIGH
BETWEEN THE
10TH–12TH SCLK
FALLING EDGE
DAISY-CHAIN MODE
DATA IS SHIFTED
FROM ONE ADC TO
THE NEXT ONE
DAISY-CHAIN MODE
DATA IS SHIFTED
FROM ONE ADC TO
THE NEXT ONE
DIN
DON'T CARE DON'T CARE CH ≠ STY CH ≠ STY DON'T CAREDON'T CARE
THE DATA WILL BE
EVENTUALLY LOST,
COMMAND3
SET CHANNEL
FOR ADC2,
COMMAND2
SET CHANNEL
FOR ADC1,
COMMAND1
CHANGE MODE
CS HIGH BETWEEN THE
10TH–13TH SCLK
FALLING EDGE
KEEP THE DEVICES IN
DAISY-CHAIN MODE
Figure 34. Daisy-Chain Diagrams—1
04351-0-032
NORMAL CONVERSION DAISY-CHAIN CYCLE
THE PARTS ENTER
DAISY-CHAIN MODE
1 16 1 10 1 10 12 14 16
SCLK
CS
DIN
DOUT
DOUT1
(DIN2)*
12
DON'T CARE DON'T CARE COMMAND3 WITH CHN ≠ STY
0, 0, CHN = MOD, VALID DATA ADC1
(0, 0, CHN = STY, VALID DATA ADC1)
DON'T CARE
0, 0, CHN ≠ MOD, VALID DATA ADC1
(0, 0, CHN
≠ STY, VALID DATA ADC1)
0, 0, CHN = MOD, VALID DATA ADC2 DON'T CARE
0, 0, CHN ≠ MOD, VALID DATA ADC2
NOTE
*INFORMATION IN BRACKETS CORRESPONDS TO DATA CLOCKED INTO DIN2 PIN
SCLK
CS
DIN
DOUT
DOUT1
(DIN2)*
COMMAND2 WITH CHN ≠ STY COMMAND1 DON'T CARE
COMMAND3 COMMAND2
0, 0, CHN = MOD, VALID DATA ADC1
(0, 0, CHN = STY, VALID DATA ADC1)
0, 0, CHN ≠ MOD, VALID DATA ADC1 COMMAND3
0, 0, CHN = MOD, VALID DATA ADC2
DAISY-CHAIN CYCLE NORMAL CONVERSION
THE PARTS ENTER
NORMAL MODE
1 10121416 1 10 13 1 16
SHIFTED INTO THE ADC1 INTERNAL REGISTER,
THIS DATA WILL BE EVENTUALLY LOST
SHIFTED INTO THE ADC2
INTERNAL REGISTER
SHIFTED INTO THE ADC1
INTERNAL REGISTER
SHIFTED INTO THE ADC1 INTERNAL REGISTER, IT
CONTAINS CHANNEL FOR NEXT CONVERSION ON ADC1
SHIFTED INTO THE ADC2
INTERNAL REGISTER
SHIFTED INTO THE ADC2 INTERNAL REGISTER, IT
CONTAINS CHANNEL FOR NEXT CONVERSION ON ADC2
Figure 35. Daisy-Chain Diagrams—II