TC1796
Peripheral Units (Vol. 2 of 2)
Synchronous Serial Interface (SSC)
User’s Manual
20-20
V2.0, 2007-07
SSC, V2.1
20.1.2.10 Slave Select Input Operation
For systems with multiple slaves, the SSC module provides seven SLSI slave select
input lines, that permit enabling or disabling of the SCLK, MTSR, and MRST signals in
Slave Mode. Slave Mode is selected by CON.MS = 0. The SLSI input logic shown in
is controlled by register PISEL and CON.
Note: In the following description, only one of the seven SLSI input lines is mentioned.
The remaining six SLSI input lines are connected to the other six inputs of the input
multiplexer, which is controlled by PISEL.SLSIS.
Figure 20-10 Slave Select Input Logic
With PISEL.SLSIS = 000
B
and Slave Mode selected, the SLSI input line does not control
the SSC I/O lines. The slave receive input signal MTSRA or MTSRB (selected by
PISEL.SRIS) and the slave clock input signal SCLKA or SCLKB (selected by
PISEL.SCIS) are passed further as MTRSI and SCLKI to the internal SSC control logic.
The slave transmit signal MRSTI from the internal SSC control logic MRSTI is passed
directly to MRST.
With PISEL.SLSIS = 001
B
, input signal SLSI controls the operation of the SSC I/O lines
as a slave select signal as follows:
MCA05785
SLSI
CON.PO
0
1
SSC Kernel
Slave Mode
To/From
Internal
Control
0
MRST
PISEL.SLSIS
Port
Control
000
001
PISEL.SRIS
MTSRA
MTSRB
SCLKA
SCLKB
PISEL.SCIS
0
1
0
1
0
1
PISEL.STIP
SCLKI
MTSRI
MRSTI
