PFS122
8bit MTP MCU with 12-bit R-Type ADC
9. Special Notes
This chapter is to remind user who use PFS122 series IC in order to avoid frequent errors upon operation.
9.1. Warning
User must read all application notes of the IC by detail before using it. Please download the related
application notes from the following link:
http://www.padauk.com.tw/tw/technical/index.aspx
9.2. Using IC
9.2.1. IO pin usage and setting
(1) IO pin is set to be digital input
When IO is set as digital input, the level of Vih and Vil would changes with the voltage and temperature.
Please follow the minimum value of Vih and the maximum value of Vil.
The value of internal pull high resistor would also changes with the voltage, temperature and pin
voltage. It is not the fixed value.
(2) If IO pin is set to be digital input and enable wake-up function
Configure IO pin as input.
Set corresponding bit to “1” in PXDIER.
If those IO pins of PA that are not used, such as PADIER [1:2], it should be set low in order to prevent
them from leakage.
(3) PA5 is set to be PRST# input pin
Configure PA5 as input.
Set CLKMD.0=1 to enable PA5 as PRST# input pin.
(4) PA7 and PA6 as external crystal oscillator
Configure PA7 and PA6 as input
Disable PA7 and PA6 internal pull-up resistor
Configure PADIER register to set PA6 and PA7 as analog input
EOSCR register bit [6:5] selects corresponding crystal oscillator frequency :
01 : for lower frequency, ex : 32KHz
10 : for middle frequency, ex : 455KHz, 1MHz
11 : for higher frequency, ex : 4MHz
Program EOSCR.7 =1 to enable crystal oscillator
Ensure EOSC working well before switching from IHRC or ILRC to EOSC
Note: Please read the PMC-APN013 carefully. According to PMC-APN013, the crystal oscillator should be
used reasonably. If the following situations happen to cause IC start-up slowly or non-startup, PADAUK
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PDK-DS-PFS122-EN_V000-May 28, 2020
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