Register 31: GPIO Peripheral Configuration (GPIOPC), offset 0xFC4
This
GPIOPC
register controls the extended drive modes of the GPIO and must be configured before
the
GPIODRnR
registers in order for extended drive mode to take effect. When the
EDE
bit in
GPIOPP
register is set and the
EDMn
bit field is non-zero, the
GPIODRnR
registers do not drive
their default value, but instead output an incremental drive strength, which has an additive effect.
This allows for more drive strength possibilities. When the
EDE
bit is set and the
EDMn
bit field is
non-zero, the 2 mA driver is always enabled. Any bits enabled in the
GPIODR4R
register will add
an additional 2 mA; any bits set in the
GPIODR8R
add an extra 4 mA of drive. The
GPIODR12R
register is only valid when the
EDMn
value is 0x3. For this encoding, setting a bit in the
GPIODR12R
register adds 4 mA of drive to the already existing 8 mA, for a 12 mA drive strength. Table
10-3 on page 753 shows the drive capability options. If
EDMn
is 0x00, then the
GPIODR2R
,
GPIODR4R
, and
GPIODR8R
function as stated in their default register description.
Table 10-13. GPIO Drive Strength Options
Drive (mA)
GPIODR2R (2mA)
GPIODR4R
(+2mA)
GPIODR8R
(+4mA)
GPIODR12R
(+4mA)
EDMn
(GPIOPC)
EDE
(GPIOPP)
2
1
0
0
N/A
0x0
X
4
0
1
0
8
0
0
1
2
N/A
0
0
N/A
0x1
1
4
N/A
1
0
6
N/A
0
1
8
N/A
1
1
2
N/A
0
0
0
0x3
1
4
N/A
1
0
0
6
N/A
0
1
0
8
N/A
1
1
0
10
N/A
0
1
1
12
N/A
1
1
1
N/A
N/A
N/A
0
1
N/A
N/A
N/A
N/A
N/A
0x2
1
June 18, 2014
800
Texas Instruments-Production Data
General-Purpose Input/Outputs (GPIOs)