LM3S601 Datasheet, PDF (134/446 Pages) List of Unclassifed Manufacturers – Microcontroller

General-Purpose Input/Outputs (GPIOs)
Configuration
GPIO Register Bit Value^a
Digital Input/Output
(UART)
Analog Input
(Comparator)
AFSEL
1
0
DIR
X
0
ODR
0
0
DEN
1
0
Digital Output
(Comparator)
1
X
0
1
a. X=Ignored (don’t care bit)
?=Can be either 0 or 1, depending on the configuration
PUR
?
0
?
PDR
?
0
?
DR2R
?
X
?
DR4R
?
X
?
DR8R
?
X
?
SLR
?
X
?
Table 8-2. GPIO Interrupt Configuration Example
Register
GPIOIS
Desired
Interrupt
Event
Trigger
0=edge
Pin 2 Bit Value^a
7
6
X
X
5
X
4
X
1=level
GPIOIBE
0=single
X
X
X
X
edge
1=both
edges
GPIOIEV 0=Low level,
X
X
X
X
or negative
edge
1=High level,
or positive
edge
GPIOIM
0=masked
0
0
0
0
1=not
masked
a. X=Ignored (don’t care bit)
3
X
X
X
0
2
0
0
1
1
1
X
X
X
0
0
X
X
X
0
8.4 Register Map
Table 8-3 on page 135 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
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
134
October 01, 2007
Preliminary