AT32F425
Series Reference Manual
2022.03.30
Page 90
Ver 2.01
6.2.10 Peripheral MUX function configuration
IOMUX function configuration as follows:
To use a peripheral pin in MUX output, it is configured as multiplexed push-pull/open-drain output.
To use a peripheral pin in MUX input, it is configured as floating input/pull-up/pull-down input.
For ADC peripherals, the pins of analog channels should be configured as analog input/output mode.
For I2C peripherals that intend to use pins as bidirectional functions, open-drain mode is required.
For USB peripherals, configure corresponding IOMUX and enable corresponding clocks
in CRM, there is no need of GPIO status configuration
6.2.11 IOMUX mapping priority
The unique peripheral multiplexed function can be configured through the GPIOx_MUXL/GPIOx_MUXH
register, except individual pins that may be directly owned by hardware.
Some pins have been directly owned by specific hardware feature, whatever GPIO configuration.
Table 6-6 Pins owned by hardware
Pin
Enable bit
Description
PA0
PWC_CTRLSTS[8] =1
Once enabled, PA0 pin acts as WKUP1 of PWC.
PA2
PWC_CTRLSTS[11] =1
Once enabled, PA2 pin acts as WKUP4 of PWC
PB5
PWC_CTRLSTS[13] =1
Once enabled, PB5 pin acts as WKUP6 of PWC
PB15
PWC_CTRLSTS[14] =1
Once enabled, PB15 pin acts as WKUP7 of PWC
PC5
PWC_CTRLSTS[12] =1
Once enabled and PC13 is not occupied, the PC15 can
be used as WKUP5 of PWC
PC13
(PWC_CTRLSTS[9] = 1) &
(
ERTC_CTRL[23: 21] =3’b000
)
&
(ERTC_CTRL[11] =0
)
&
(
ERTC_TAMP[0] = 0
)
Once enabled, PC13 pin acts as WKUP2 of PWC
PC13
(
ERTC_CTRL[23: 21] !=3’b000
)
|
(
ERTC_CTRL[11] !=0
)
|
(
ERTC_TAMP[0] != 0
)
Once enabled, the PC13 is used as RTC channel input
and output
PC14
CMR_BPDC[0]=1
Once enabled, the PC14 is used as LEXT channel
PC15
CMR_BPDC[0]=1
Once enabled, the PC15 is used as LEXT channel
PF0
CMR_CTRL[16]=1
Once enabled, the PF0 is used as LEXT channel
PF1
CMR_CTRL[16]=1&
CMR_CTRL[18]=0
Once enabled, the PF1 is used as HEXT channel
6.2.12 External interrupt/wake-up lines
Each pin can be used as an external interrupt input. The corresponding pin should be configured as
input mode.
6.3
GPIO registers
lists GPIO register map and their reset values. These peripheral registers must be
accessed by bytes (8 bits), half-words (16 bits) or words (32 bits).
Table 6-7 GPIO register map and reset values
Register
Offset
Reset value
GPIOA_CFGR
0x00
0x2800 0000
GPIOx_CFGR(x = B,C,D,F)
0x00
0x0000 0000
GPIOx_OMODER
0x04
0x0000 0000
GPIOx_ODRVR
0x08
0x0C00 0000(A)
0x0000 0000
GPIOA_PULL
0x0C
0x2400 0000(A)
GPIOx_PULL(x = B,C,D,F)
0x0C
0x0000 0000
GPIOx_IDT
0x10
0x0000 XXXX