HBCR-1610 Datasheet, PDF (7/10 Pages) Agilent(Hewlett-Packard) – Single Chip Bar Code Decode IC

Parallel I/O Handshake
COMMANDS RECEIVED BY THE IC
CDY ₁
CRD
2
D_1-8
3
4
5
6
7
PROTOCOL
1. THE HOST INDICATES THAT A COMMAND
IS PENDING BY LOWERING CDY.
2. THE IC INDICATES THAT IT IS READY FOR
A COMMAND BY LOWERING CRD.
3. THE HOST OUTPUTS THE COMMAND
ONTO THE DATA BUS.
4. THE HOST INDICATES THAT THE DATA
IS STABLE BY RAISING CDY.
5. THE IC READS THE COMMAND FROM
THE BUS.
6. THE IC INDICATES THAT THE COMMAND
WAS ACCEPTED BY RAISING CRD.
7. THE HOST REMOVES THE DATA FROM
THE DATA BUS.
DATA TRANSMITTED FROM THE IC
RTS ₁
DDY
2
D_1-8
DWR
3
4
5
7
6
PROTOCOL
1. THE IC INDICATES DATA IS READY
TO BE TRANSMITTED BY LOWERING
RTS; RTS STAYS LOW UNTIL THE LAST
BYTE HAS BEEN TRANSMITTED.
2. THE HOST SIGNALS THE IC THAT IT IS
READY FOR DATA BY LOWERING DDY.
3. THE IC OUTPUTS DATA ONTO THE BUS.
4. THE IC INDICATES THAT THE DATA
IS STABLE BY LOWERING DWR.
5. THE HOST ACKNOWLEDGES THAT THE
DATA IS RECEIVED BY RAISING DDY.
6. THE IC INDICATES THE END OF THE
OUTPUT CYCLE BY RAISING DWR.
7. THE IC REMOVES DATA FROM THE BUS.
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