Rainbow Electronics DS1957 - Manual (Page 10)

DS1957
10 of 25
DATA TRANSFER AND CONTROL FUNCTION FLOW CHART Figure 4 (cont’d)
E1H
READ STATUS
?
N
BUS MASTER RX
NUMBER OF FREE BYTES
IN INPUT BUFFER
Y
1)
FROM DATA TRANSFER AND
CONTROL FUNCTION
FLOW CHART PART 3
N
Y
TO DATA TRANSFER AND
CONTROL FUNCTION
FLOW CHART PART 3 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
BUS MASTER TX OWUS
STATUS BYTE
1)
D2H
WRITE STATUS
?
CRC CORRECT
?
BUS MASTER
TX RESET
?
2)
N
N
Y
BUS MASTER RX
NUMBER OF USED BYTES
IN OUTPUT BUFFER
1)
BUS MASTER RX OWMS
REGISTER CONTENTS
1)
BUS MASTER RX CPST
REGISTER CONTENTS
1)
BUS MASTER RX
CRC 16 OF COMMAND
AND DATA BYTES
1)
BUS MASTER
TX RESET
?
2)
N
Y
BUS MASTER
TX RESET
?
2)
N
Y
COMMAND
UNDERSTOOD
?
BUS MASTER
RX 0’s
BUS MASTER
RX 1’s
N Y
1) 1)
BUS MASTER TX 517FH
RELEASE SEQUENCE
1)
BUS MASTER RX
CRC 16 OF COMMAND
AND OWUS BYTE
1)
Y
BUS MASTER
RX 1’s
1)