LM3S3748 Datasheet, PDF (257/753 Pages) List of Unclassifed Manufacturers – Microcontroller

LM3S3748 Microcontroller
■ GPIO Port H (legacy): 0x4002.7000
■ GPIO Port H (high-speed): 0x4005.F000
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, GPIOPUR, and GPIODEN registers are
0x0000.0000 for all GPIO pins, with the exception of the four JTAG/SWD pins (PC[3:0]).
These four pins default to JTAG/SWD functionality. Because of this, the default reset value
of these registers for Port C is 0x0000.000F.
The default register type for the GPIOCR register is RO for all GPIO pins, with the exception
of the NMI pin and the four JTAG/SWD pins (PB7 and PC[3:0]). These five pins are
currently the only GPIOs that are protected by the GPIOCR register. Because of this, the
register type for GPIO Port B7 and GPIO Port C[3:0] is R/W.
The default reset value for the GPIOCR register is 0x0000.00FF for all GPIO pins, with the
exception of the NMI pin and the four JTAG/SWD pins (PB7 and PC[3:0]). To ensure that
the JTAG port is not accidentally programmed as a GPIO, these four pins default to
non-committable. To ensure that the NMI pin is not accidentally programmed as the
non-maskable interrupt pin, it defaults to non-committable. Because of this, the default reset
value of GPIOCR for GPIO Port B is 0x0000.007F while the default reset value of GPIOCR
for Port C is 0x0000.00F0.
Table 10-3. GPIO Register Map
Offset Name
Type
0x000 GPIODATA
0x400 GPIODIR
0x404 GPIOIS
0x408 GPIOIBE
0x40C GPIOIEV
0x410 GPIOIM
0x414 GPIORIS
0x418 GPIOMIS
0x41C GPIOICR
0x420 GPIOAFSEL
0x500 GPIODR2R
0x504 GPIODR4R
0x508 GPIODR8R
0x50C GPIOODR
0x510 GPIOPUR
R/W
R/W
R/W
R/W
R/W
R/W
RO
RO
W1C
R/W
R/W
R/W
R/W
R/W
R/W
Reset
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
-
0x0000.00FF
0x0000.0000
0x0000.0000
0x0000.0000
-
Description
GPIO Data
GPIO Direction
GPIO Interrupt Sense
GPIO Interrupt Both Edges
GPIO Interrupt Event
GPIO Interrupt Mask
GPIO Raw Interrupt Status
GPIO Masked Interrupt Status
GPIO Interrupt Clear
GPIO Alternate Function Select
GPIO 2-mA Drive Select
GPIO 4-mA Drive Select
GPIO 8-mA Drive Select
GPIO Open Drain Select
GPIO Pull-Up Select
See
page
259
260
261
262
263
264
265
266
268
269
271
272
273
274
275
April 08, 2008
257
Preliminary