wm8350 Wolfson Microelectronics plc, wm8350 Datasheet - Page 187

• Manufacturer Part Number: wm8350
• Description: Wolfson Audioplus? Stereo Codec With Power Management
• Manufacturer: Wolfson Microelectronics plc

Production Data
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20.2.2
The function of each GPIO pin is programmable by writing to the respective GPn register bits.
GPn_FN = 0000 selects the GPIO function and settings other than 0000 select various alternate
functions.
The GPIO function is also determined by the value of the GPn_DIR register bit. Note that, when
changing GPn_DIR, it is recommended to set GPn_FN = 0000 first.
When changing the function of a GPIO pin, (updating GPn_FN or GPn_DIR), it is recommended that
the following sequence of actions is taken sequentially.
Note that GPIO7 is automatically enabled as CSB in 3-wire and 4-wire control modes. GPIO6 is
automatically enabled as SDOUT in 4-wire control mode. These automatic selections take
precedence over all other GPIO6 and GPIO7 control fields.
R140 (8Ch
GPIO function
select 1
R141 (8Dh)
GPIO function
select 2
R142 (8Eh)
GPIO function
select 3
R143 (8Fh)
Table 124 Control Registers to Select GPIO Alternate Functions
ADDRESS






SELECTING GPIO ALTERNATE FUNCTIONS
Set GPn_FN = 0000
Update the other GPIO configuration fields GPn_DB, GPn_PU, GPn_PD, GPn_CFG,
GPn_DIR
If the new function is an input, ensure that the input trigger is in the inactive state (ie. logic
0 for a function that is active High)
Set GPn_FN according to the new GPIO function
Read the GPIO Interrupt Status Register R30 (1Eh) to clear any GPIO Interrupt events
If any bit in Register R30 (1Eh) was set when read, then read the System Interrupts
Register R24 (18h) to clear the IRQ pin
BIT
15:12
15:12
15:12
11:8
11:8
11:8
3:0
7:4
3:0
7:4
3:0
7:4
3:0
GP0_FN
GP1_FN
GP2_FN
GP3_FN
GP4_FN
GP5_FN
GP6_FN
GP7_FN
GP8_FN
GP9_FN
GP10_FN
GP11_FN
GP12_FN
LABEL
Dependan
t on
CONFIG
settings
DEFAULT
Selects function of GPIO0
Selects function of GPIO1
Selects function of GPIO2
Selects function of GPIO3
Selects function of GPIO4
Selects function of GPIO5
Selects function of GPIO6
Selects function of GPIO7
Selects function of GPIO8
Selects function of GPIO9
Selects function of GPIO10
Selects function of GPIO11
Selects function of GPIO12
DESCRIPTION
PD, June 2009, Rev 4.1
WM8350
187