LM3S613 Datasheet, PDF (238/591 Pages) List of Unclassifed Manufacturers – Microcontroller

General-Purpose Input/Outputs (GPIOs)
Table 7-5. GPIO Interrupt Configuration Example (continued)
Desired
Pin 2 Bit Value^a
Register
Interrupt
Event
7
6
5
4
3
Trigger
GPIOIBE
0=single
X
X
X
X
X
edge
1=both
edges
GPIOIEV 0=Low level,
X
X
X
X
X
or negative
edge
1=High level,
or positive
edge
GPIOIM
0=masked
0
0
0
0
0
1=not
masked
a. X=Ignored (don’t care bit)
2
0
1
1
1
X
X
0
0
X
X
0
7.5 Register Map
Table 7-6 on page 238 lists the GPIO registers. The offset listed is a hexadecimal increment to the
register’s address, relative to that GPIO port’s base address:
■ GPIO Port A: 0x4000.4000
■ GPIO Port B: 0x4000.5000
■ GPIO Port C: 0x4000.6000
■ GPIO Port D: 0x4000.7000
■ GPIO Port E: 0x4002.4000
Note that the GPIO module clock must be enabled before the registers can be programmed (see
page 203). There must be a delay of 3 system clocks after the GPIO module clock is enabled before
any GPIO module registers are accessed.
Important: The GPIO registers in this chapter are duplicated in each GPIO block; however,
depending on the block, all eight bits may not be connected to a GPIO pad. In those
cases, writing to those unconnected bits has no effect, and reading those unconnected
bits returns no meaningful data.
Note:
The default reset value for the GPIOAFSEL register is 0x0000.0000 for all GPIO pins, with
the exception of the five JTAG pins (PB7 and PC[3:0]). These five pins default to JTAG
functionality. Because of this, the default reset value of GPIOAFSEL for GPIO Port B is
0x0000.0080 while the default reset value for Port C is 0x0000.000F.
Table 7-6. GPIO Register Map
Offset Name
Type
0x000 GPIODATA
R/W
0x400 GPIODIR
R/W
0x404 GPIOIS
R/W
Reset
0x0000.0000
0x0000.0000
0x0000.0000
Description
GPIO Data
GPIO Direction
GPIO Interrupt Sense
See
page
240
241
242
238
July 14, 2014
Texas Instruments-Production Data