SYNCHRONOUS SERIAL INTERFACE (SSI)
MOTOROLA
PORT C
6 - 79
Table 6-5 Definition of SC0, SC1, SC2, and SCK
TXC – Transmitter Clock
RXC – Receiver Clock
*XC – Transmitter/Receiver Clock
(synchronous operation)
FST – Transmitter Frame Sync
SSI Pin Name
(Control Bit Name)
Asynchronous (SYN=0)
Synchronous (SYN=1)
Continuous Clock
(GCK=0)
Gated Clock
(GCK=1)
Continuous Clock
(GCK=0)
Gated Clock
(GCK=1)
SC0=0 (in)
RXC External
RXC External
Input F0
Input F0
SC0=1 (out)
(SCD0)
RXC Internal
RXC Internal
Output F0
Output F0
SC1=0 (in)
FSR External
Not Used
Input F1
Input F1
SC1=1 (out)
(SCD1)
FSR Internal
FSR Internal
Output F1
Output F1
SC2=0 (in)
FST External
Not Used
FS* External
Not Used
SC2=1 (out)
(SCD2)
FST Internal
FST Internal
FS* Internal
FS* Internal
SCK=0 (in)
TXC External
TXC External
*XC External
*XC External
SCK=1 (out
(SCKD)
TXC Internal
TXC Internal)
*XC Internal
*XC Internal
FSR – Receiver Frame Sync
FS* – Transmitter/Receiver Frame Sync
(synchronous operation)
F0 – Flag 0
F1 – Flag 1
Table 6-6 SSI Clock Sources, Inputs, and Outputs
EXT – External Pin Name
INT – Internal Bit Clock
SYN
SCKD
SCD0
R Clock
Source
RX Clock
Out
T Clock Source
TX Clock Out
Asynchronous
0
0
0
EXT, SC0
–
EXT, SCK
–
0
0
1
INT
SC0
EXT, SCK
–
0
1
0
EXT, SC0
–
INT
SCK
0
1
1
INT
SC0
INT
SCK
Synchronous
1
0
0
EXT, SCK
–
EXT, SCK
–
1
0
1
EXT, SCK
–
EXT, SCK
–
1
1
0
INT
SCK
INT
SCK
1
1
1
INT
SCK
INT
SCK
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Freescale Semiconductor, Inc.
For More Information On This Product,
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