AN1313 - APPLICATION NOTE

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2.

Configuration 2: external memory exists in page 3 and is below 2K Byte size.

Impact: one register to configure, the external memory has to be remapped within page 3.

Work-around: Set the bit XRAM2EN and clear the bit XRAM1EN of XPERCON new register. Then

remap your variables to uses the XRAM2 range as your XRAM (bigger than the ST10F168 so no

issue) and remap your 2K Byte range of external memory at the XRAM1 location. This way you keep

everything within page 3.

3.

Configuration 3: external memory exists in page 3 and is above 2K Byte size.

Impact: one register to configure, the external memory to be remapped in another page.

Work-around: Set the bit XRAM2EN of the XPERCON new register and relocate your external

memory in page 2 (address range 0x8000 - 0xBFFF) if possible. Then change the link directives

according to the new mapping.

Note:

The setting of the bits in XPERCON must be done before enabling the XBus Peripherals by the

XPEN bit of SYSCON.

2.3 - Flash EEPROM

The ST10F168 and the ST10F269 don’t have the same Flash memories. The embedded Flash of the

ST10F269 has a technology really similar to the stand-alone Flash memories of STMicroelectronics.

2.3.1 - Hardware Impacts

The 12 Volts input on pin 84 is no longer needed.

2.3.2 - Software Impacts

The mapping of the application and the programming and erasing routines are impacted.

ST10F168 bank 0: this range is fully compatible with the block 0 of the ST10F269.

ST10F168 bank 1: this range is now covered by the blocks 1, 2 and 3 of the ST10F269. It is not

mandatory to re-map Code and Data: these 3 blocks could be considered as a single range.

ST10F168 bank 2 and bank 3: The highest third of bank 2 and the lowest third of bank 3 correspond to

the block 5 of the ST10F269. Code and Data have to be remapped to take care of this separation in three

ranges of 64K Bytes if these banks were likely to be independently reprogrammed.

The programming-erasing software must also be rewritten as the ST10F269 does not work with the

Table 1 : Flash Memories Key Characteristics

ST10F168

ST10F269

Flash Size

256K Bytes

256K Bytes

Flash Organization

4 banks

7 blocks

Programming voltage

12 Volts

5 Volts

Programming method

Write/Erase Controller

Program/Erase cycles

10 000, 20 years of data retention

100.000,