SN250 datasheet(117/130 Pages) STMICROELECTRONICS

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SN250

SIF module programming and debug interface

117/130

SIF module programming and debug interface

SIF is a synchronous serial interface developed by Cambridge Consultants Ltd. It is the

primary programming and debug interface of the SN250. Therefore, any design

implementing the SN250 should make the SIF signals readily available. The SIF module

allows external devices to read and write memory-mapped registers in real-time without

changing the functionality or timing of the XAP2b core. See the SN250 Reference Design

for details regarding the implementation of the SIF interface.

The SIF interface provides the following:

●

IC production test (especially analog)

●

PCB production test

●

XAP2b code development

●

Product control and characterization

The pins are:

●

nSIF_LOAD

●

SIF_CLK

●

SIF_MOSI

●

SIF_MISO

Because the SIF module directly connects to the program and data memory buses within

the SN250, it has access to the entire Flash and RAM blocks, as well as the on-chip

registers.

The maximum serial shift speed for the SIF interface is 48MHz. SIF interface accesses can

be initiated even when the chip is in idle and deep sleep modes. An edge on nSIF_LOAD

wakes the chip to allow SIF cycles.

SN250 Datasheet(PDF) 117 Page - STMicroelectronics