Rainbow Electronics DS1957 - Manual (Page 7)

DS1957
7 of 25
DATA TRANSFER AND CONTROL FUNCTION FLOW CHART Figure 4
MASTER TX DATA TRANSFER OR
CONTROL FUNCTION COMMAND
0FH
WRITE IPR
?
AAH
READ IPR
?
N
BUS MASTER TX
LENGTH BYTE
BUS MASTER TX
DATA BYTE
LAST BYTE
?
DS1957 INCREMENTS
IPR ADDRESS
BUS MASTER RX
CRC 16 OF COMMAND,
LENGTH BYTE, DATA
BUS MASTER
TX RESET
?
TO DATA TRANSFER AND
CONTROL FUNCTION
Y
Y
N
FROM ROM FUNCTION FLOW CHART
1)
1)
2)
1) TO BE TRANSMITTED OR RECEIVED AT OVERDRIVE SPEED IF OD=1
2) RESET PULSE TO BE TRANSMITTED AT OVERDRIVE SPEED IF OD=1;
RESET PULSE TO BE TRANSMITTED AT REGULAR SPEED IF OD=0
OR IF THE DS1957 IS TO BE RESET FROM OVERDRIVE SPEED TO
REGULAR SPEED
1)
BUS MASTER TX
LENGTH BYTE
BUS MASTER RX
DATA BYTE
LAST BYTE
?
DS1957 INCREMENTS
IPR ADDRESS
BUS MASTER RX
CRC 16 OF COMMAND,
LENGTH BYTE, DATA
BUS MASTER
TX RESET
?
FLOW CHART PART 2
LEGEND:
DECISION MADE
BY THE MASTER
DECISION MADE
BY DS1957
1)
Y
N
Y
Y
N
N
1)
1)
2)
1)
Y
TO DATA TRANSFER AND
CONTROL FUNCTION
FLOW CHART PART 2
SEE COMMAND
DESCRIPTION
FOR DETAILS
BUS MASTER
RX 1’s
BUS MASTER
TX RESET
?
N
Y
2)
1)
N