ON-CHIP EMULATION (OnCE) PINS
MOTOROLA
DSP56002 PIN DESCRIPTIONS
2 - 11
2.2.7.2
Serial Control One (SC1)
The SSI uses this bidirectional pin to control flag or frame synchronization. This pin’s func-
tion is determined by whether the SCLK is in synchronous or asynchronous mode.In
asynchronous mode, this pin is frame sync I/O. For synchronous mode with continuous
clock, this pin is serial flag SC1 and operates like the SC0. SC0 and SC1 are independent
serial I/O flags but may be used together for multiple serial device selection. SC1 can be
programmed as a general-purpose I/O pin (PC4) when the SSI SC1 function is not being
used, and it is configured as a GPIO input pin during hardware reset.
2.2.7.3
Serial Control Two (SC2)
The SSI uses this bidirectional pin to control frame synchronization only. As with SC0 and
SC1, its function is defined by the SSI operating mode. SC2 can be programmed as a
general-purpose I/O pin (PC5) when the SSI SC2 function is not being used, and it is con-
figured as a GPIO input pin during hardware reset.
2.2.7.4
SSI Serial Clock (SCK)
This bidirectional pin provides the serial bit rate clock for the SSI when only one clock is
being used. SCK can be programmed as a general-purpose I/O pin (PC6) when it is not
needed as an SSI pin, and it is configured as a GPIO input pin during hardware reset.
2.2.7.5
SSI Receive Data (SRD)
This input pin receives serial data into the SSI receive shift register. SRD can be pro-
grammed as a general-purpose I/O pin (PC7) when it is not needed as an SSI pin, and it
is configured as a GPIO input pin during hardware reset.
2.2.7.6
SSI Transmit Data (STD)
This output pin transmits serial data from the SSI transmit shift register. STD can be pro-
grammed as a general-purpose I/O pin (PC8) when it is not needed as an SSI pin, and it
is configured as a GPIO input pin during hardware reset.
2.3
ON-CHIP EMULATION (OnCE) PINS
The following paragraphs describe the OnCE pins associated with the OnCE controller
and its serial interface.
2.3.1
Debug Serial Input/Chip Status 0 (DSI/OS0)
Serial data or commands are provided to the OnCE controller through the DSI/OS0 pin
when it is an input. The data received on the DSI pin will be recognized only when the
DSP56K has entered the debug mode of operation. Data is latched on the falling edge of
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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