Rainbow Electronics DS1957 - Manual (Page 8)

DS1957
8 of 25
DATA TRANSFER AND CONTROL FUNCTION FLOW CHART Figure 4 (cont’d)
2DH
WRITE I/O
BUFFER
?
N
BUS MASTER TX
LENGTH BYTE
BUS MASTER TX
DATA BYTE
LAST BYTE
?
DS1957 INCREMENTS
BUFFER ADDRESS
BUS MASTER RX
CRC 16 OF COMMAND,
LENGTH BYTE, DATA
CRC CORRECT
?
FROM DATA TRANSFER
AND CONTROL
FUNCTION
Y
Y
N
1)
1)
N
FLOW CHART PART 3
1)
Y
FROM DATA TRANSFER AND
CONTROL FUNCTION
FLOW CHART PART 1
TO DATA TRANSFER AND
CONTROL FUNCTION
FLOW CHART PART 3
TO ROM FUNCTIONS
FLOW CHART
BUS MASTER TX 9DB3H
RELEASE SEQUENCE
COMMAND
UNDERSTOOD
?
BUS MASTER
TX RESET
?
BUS MASTER
RX 0’s
BUS MASTER
RX 1’s
22H
READ I/O
BUFFER
?
N
BUS MASTER TX
LENGTH BYTE
BUS MASTER RX
DATA BYTE
LAST BYTE
?
DS1957 DECREMENTS
BUFFER ADDRESS
BUS MASTER RX
CRC 16 OF COMMAND,
LENGTH BYTE, DATA
CRC CORRECT
?
Y
Y
N
1)
1)
1)
Y
BUS MASTER TX 624CH
RELEASE SEQUENCE
BUS MASTER
RX 0’s
BUS MASTER
RX 1’s
BUS MASTER
TX RESET
?
1) 1)
N N Y Y
1)
1)
1) 1)
N
N
N
2)
2) 2)
Y
Y
Y
FROM DATA TRANSFER
AND CONTROL
FUNCTION
FLOW CHART PART 1
1), 2) SEE PREVIOUS OR NEXT PAGE
N
COMMAND
UNDERSTOOD
?
BUS MASTER
TX RESET
?
BUS MASTER
TX RESET
?
2)
Y
BUS MASTER
RX 1’s
1)
N