LM3S5762 Datasheet, PDF (170/841 Pages) Texas Instruments – Stellaris® LM3S5762 Microcontroller

System Control
5 System Control
System control determines the overall operation of the device. It provides information about the
device, controls the clocking to the core and individual peripherals, and handles reset detection and
reporting.
5.1 Signal Description
Table 5-1 on page 170 lists the external signals of the System Control module and describes the
function of each. The NMI signal is the alternate function for and functions as a GPIO after reset.
under commit protection and require a special process to be configured as any alternate function
or to subsequently return to the GPIO function, see “Commit Control” on page 356. The column in
the table below titled "Pin Assignment" lists the GPIO pin placement for the NMI signal. The AFSEL
bit in the GPIO Alternate Function Select (GPIOAFSEL) register (page 370) should be set to choose
the NMI function. For more information on configuring GPIOs, see “General-Purpose Input/Outputs
(GPIOs)” on page 350. The remaining signals (with the word "fixed" in the Pin Assignment column)
have a fixed pin assignment and function.
Table 5-1. System Control & Clocks Signals (64LQFP)
Pin Name
Pin Number Pin Type Buffer Type^a Description
NMI
55
I
TTL
Non-maskable interrupt.
OSC0
30
I
Analog Main oscillator crystal input or an external clock reference
input.
OSC1
31
O
Analog Main oscillator crystal output. Leave unconnected when using
a single-ended clock source.
RST
40
I
TTL
System reset input.
a. The TTL designation indicates the pin has TTL-compatible voltage levels.
5.2 Functional Description
The System Control module provides the following capabilities:
■ Device identification (see “Device Identification” on page 170)
■ Local control, such as reset (see “Reset Control” on page 170), power (see “Power
Control” on page 175) and clock control (see “Clock Control” on page 175)
5.2.1
5.2.2
5.2.2.1
■ System control (Run, Sleep, and Deep-Sleep modes); see “System Control” on page 181
Device Identification
Several read-only registers provide software with information on the microcontroller, such as version,
part number, SRAM size, flash size, and other features. See the DID0, DID1, and DC0-DC7 registers.
Reset Control
This section discusses aspects of hardware functions during reset as well as system software
requirements following the reset sequence.
Reset Sources
The controller has six sources of reset:
170
November 17, 2011
Texas Instruments-Production Data