
General-purpose and alternate-function I/Os (GPIOs and AFIOs)
RM0008
166/1096
Doc ID 13902 Rev 12
9.2.2 Port
configuration
register high (GPIOx_CRH) (x=A..G)
Address offset: 0x04
Reset value: 0x4444 4444
9.2.3
Port input data register (GPIOx_IDR) (x=A..G)
Address offset: 0x08h
Reset value: 0x0000 XXXX
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
CNF15[1:0]
MODE15[1:0]
CNF14[1:0]
MODE14[1:0]
CNF13[1:0]
MODE13[1:0]
CNF12[1:0]
MODE12[1:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
CNF11[1:0]
MODE11[1:0]
CNF10[1:0]
MODE10[1:0]
CNF9[1:0]
MODE9[1:0]
CNF8[1:0]
MODE8[1:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bits 31:30, 27:26,
23:22, 19:18, 15:14,
11:10, 7:6, 3:2
CNFy[1:0]:
Port x configuration bits (y= 8 .. 15)
These bits are written by software to configure the corresponding I/O port.
Refer to
Table 20: Port bit configuration table on page 156
In input mode (MODE[1:0]=00)
:
00: Analog mode
01: Floating input (reset state)
10: Input with pull-up / pull-down
11: Reserved
In output mode (MODE[1:0]
>
00)
:
00: General purpose output push-pull
01: General purpose output Open-drain
10: Alternate function output Push-pull
11: Alternate function output Open-drain
Bits 29:28, 25:24,
21:20, 17:16, 13:12,
9:8, 5:4, 1:0
MODEy[1:0]:
Port x mode bits (y= 8 .. 15)
These bits are written by software to configure the corresponding I/O port.
Refer to
Table 20: Port bit configuration table on page 156
00: Input mode (reset state)
01: Output mode, max speed 10 MHz.
10: Output mode, max speed 2 MHz.
11: Output mode, max speed 50 MHz.
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
IDR15
IDR14
IDR13
IDR12
IDR11
IDR10
IDR9
IDR8
IDR7
IDR6
IDR5
IDR4
IDR3
IDR2
IDR1
IDR0
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
Bits 31:16
Reserved, always read as 0.
Bits 15:0
IDRy[15:0]:
Port input data (y= 0 .. 15)
These bits are read only and can be accessed in Word mode only. They contain the input
value of the corresponding I/O port.