
DocID024597 Rev 5
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RM0351
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The data bus width is 36 bits because 4 bits are available for parity check (1 bit per byte) in
order to increase memory robustness, as required for instance by Class B or SIL norms.
The parity bits are computed and stored when writing into the SRAM2. Then, they are
automatically checked when reading. If one bit fails, an NMI is generated. The same error
can also be linked to the BRK_IN Break input of TIM1/TIM8/TIM15/TIM16/TIM17, with the
SPL control bit in the
SYSCFG configuration register 2 (SYSCFG_CFGR2)
. The SRAM2
Parity Error flag (SPF) is available in the
SYSCFG configuration register 2
Note:
When enabling the RAM parity check, it is advised to initialize by software the whole RAM
memory at the beginning of the code, to avoid getting parity errors when reading non-
initialized locations.
2.4.2
SRAM2 Write protection
The SRAM2 can be write protected with a page granularity of 1 Kbyte.
Table 3. SRAM2 organization
Page number
Start address
End address
Page 0
0x1000 0000
0x1000 03FF
Page 1
0x1000 0400
0x1000 07FF
Page 2
0x1000 0800
0x1000 0BFF
Page 3
0x1000 0C00
0x1000 0FFF
Page 4
0x1000 1000
0x1000 13FF
Page 5
0x1000 1400
0x1000 17FF
Page 6
0x1000 1800
0x1000 1BFF
Page 7
0x1000 1C00
0x1000 1FFF
Page 8
0x1000 2000
0x1000 23FF
Page 9
0x1000 2400
0x1000 27FF
Page 10
0x1000 2800
0x1000 2BFF
Page 11
0x1000 2C00
0x1000 2FFF
Page 12
0x1000 3000
0x1000 33FF
Page 13
0x1000 3400
0x1000 37FF
Page 14
0x1000 3800
0x1000 3BFF
Page 15
0x1000 3C00
0x1000 3FFF
Page 16
0x1000 4000
0x1000 43FF
Page 17
0x1000 4400
0x1000 47FF
Page 18
0x1000 4800
0x1000 4BFF
Page 19
0x1000 4C00
0x1000 4FFF
Page 20
0x1000 5000
0x1000 53FF
Page 21
0x1000 5400
0x1000 57FF
Page 22
0x1000 5800
0x1000 5BFF