SYNCHRONOUS SERIAL INTERFACE (SSI)
6 - 104
PORT C
MOTOROLA
6.4.5
SSI Initialization
The correct way to initialize the SSI is as follows:
1. Hardware, software, SSI individual, or STOP reset
2. Program SSI control registers
3. Configure SSI pins (at least one) as not general-purpose I/O
During program execution, CC8–CC3 may be cleared, causing the SSI to stop serial activity
and enter the individual reset state. All status bits of the interface will be set to their reset
state; however, the contents of CRA and CRB are not affected. This procedure allows the
DSP program to reset each interface separately from the other internal peripherals.
The DSP program must use an SSI reset when changing the MOD, GCK, SYN, SCKD,
SCD2, SCD1, or SCD0 bits to ensure proper operation of the interface. Figure 6-49 is a
flowchart illustrating the three initialization steps previously listed. Figure 6-50, Figure
6-51, and Figure 6-52 provide additional detail to the flowchart.
HARDWARE OR SOFTWARE REST
PROGRAM CRA AND CRB
SELECT PINS TO BE USED
PORT C CONTROL REGISTER
Figure 6-49 SSI Initialization Block Diagram
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