AN2169 Datasheet, PDF (20/33 Pages) STMicroelectronics – Porting an application from the ST10F168 to the ST10F276

Modified registers
AN2169
Bit
Function
WDTR: Watchdog Timer Reset Indication Flag
1
Set by the watchdog timer on an overflow.
Cleared by a hardware reset or by the SRVWDT instruction.
WDTIN: Watchdog Timer Input Frequency Selection
0
0:Input frequency is Fcpu /2
1:Input frequency is Fcpu /128
Note: 1 More than one RESET indication flag may be set. After EINIT, all flags are cleared.
2 Power-on is detected when a rising edge from VDD=0 V to VDD<2.0 V is recognized.
3.1.1 Hardware impact
None.
3.1.2 Software impact
None if the ST10F168 software was masking the non-implemented bits.
3.2 PICON register
Some bits have been added, and some suppressed in this register for the ST10F276.
The port Input Control register PICON is used to select between TTL and CMOS-like input
thresholds.
The CMOS-like input thresholds are defined above the TTL levels and feature a defined
hysteresis to prevent the inputs from toggling while the respective input signal level is near the
thresholds.
On the ST10F168, this functionality is available for pins of port 2, port3, port7 and port8 and the
hysteresis level is 300 mV for CMOS levels.
In the ST10F276, this functionality has been added for the pins of port 4 and port 6.
Moreover the default hysteresis is now 500 mV for TTL levels and is 800 mV for CMOS levels.
ST10F168: PICON (F1C4h /E2h)
ESFR
Reset Value: 0000h
15
14
13 12
11
10
9
8
7
6
5
P8LOUT P7LOUT -
P3HOUT P3LOUT P2HOUT P2LOUT P8LIN P7LIN
RW
RW
RW
RW
RW
RW
RW RW
4
3
2
1
0
P3HIN P3LIN P2HIN P2LIN
RW RW RW RW
ST10F276: PICON (F1C4h / E2h)
ESFR
20/33