ST92F150-EVAL STMicroelectronics, ST92F150-EVAL Datasheet - Page 409

• Manufacturer Part Number: ST92F150-EVAL
• Description: BOARD EVALUATION FOR ST9 SERIES
• Manufacturer: STMicroelectronics

Specifications of ST92F150-EVAL

• Processor To Be Evaluated: ST90158 and ST92F1x Daughter Board
• Interface Type: I2C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 497-2905

KNOWN LIMITATIONS (Cont’d)
13.2 FLASH CORRUPTION WHEN EXITING STOP MODE
Description
Under very specific conditions, the first read per-
formed in flash memory by the core when exiting
stop mode may be corrupted.
Impact on application
As this first read is an opcode, this corruption may
lead to an unpredictable behavior of the applica-
tion.
RRx is an unused register in the register file.
Implementation
And replace the actual STOP bit setting sequence
(specified in datasheet):
nop
ldw RRx,0
WU_CTLR = WUm_wuit | WUm_id1s | WUm_stop;
WU_CTLR = WUm_wuit | WUm_id1s;
WU_CTLR = WUm_wuit | WUm_id1s | WUm_stop;
#pragma register_file
volatile unsigned int
spp(WU_PG);
asm("nop");
asm("nop");
asm("nop");
Dummy_16bit_data
Dummy_16bit_data;
ST92F124/F150/F250 - KNOWN LIMITATIONS
Workaround
Description
In ST92F124/F150/F250 datasheet, there is a
warning in the WUCTRL register description:
“In order to avoid to execute register write instruc-
tions after a correct STOP bit setting sequence
and before entering the STOP mode, it is manda-
tory to execute 3 NOP instructions after the STOP
bit setting sequence.”
The workaround is to replace these 3 NOPs by the
following assembly code:
In a C language software, implement the following
code.
Declare a dummy variable in the register file (for
example in RR0 16-bit register)
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