LM3S310 Luminary Micro, Inc, LM3S310 Datasheet - Page 26

• Manufacturer Part Number: LM3S310
• Description: Lm3s310 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Architectural Overview
1.4.5
1.4.5.1
1.4.5.2
1.4.5.3
1.4.6
1.4.6.1
26
The SSI module can be configured as either a master or slave device. As a slave device, the SSI
module can also be configured to disable its output, which allows a master device to be coupled
with multiple slave devices.
The SSI module also includes a programmable bit rate clock divider and prescaler to generate the
output serial clock derived from the SSI module’s input clock. Bit rates are generated based on the
input clock and the maximum bit rate is determined by the connected peripheral.
System Peripherals
Programmable GPIOs (Section 8 on page 103)
General-purpose input/output (GPIO) pins offer flexibility for a variety of connections.
The Stellaris GPIO module is composed of five physical GPIO blocks, each corresponding to an
individual GPIO port. The GPIO module is FiRM-compliant (compliant to the ARM Foundation IP
for Real-Time Microcontrollers specification) and supports 3 to 36 programmable input/output pins.
The number of GPIOs available depends on the peripherals being used (see Table 16-4 on
page 319 for the signals available to each GPIO pin).
The GPIO module features programmable interrupt generation as either edge-triggered or
level-sensitive on all pins, programmable control for GPIO pad configuration, and bit masking in
both read and write operations through address lines.
Three Programmable Timers (Section 9 on page 141)
Programmable timers can be used to count or time external events that drive the Timer input pins.
The Stellaris General-Purpose Timer Module (GPTM) contains three GPTM blocks. Each GPTM
block provides two 16-bit timer/counters that can be configured to operate independently as timers
or event counters, or configured to operate as one 32-bit timer or one 32-bit Real-Time Clock
(RTC).
When configured in 32-bit mode, a timer can run as a one-shot timer, periodic timer, or Real-Time
Clock (RTC). When in 16-bit mode, a timer can run as a one-shot timer or periodic timer, and can
extend its precision by using an 8-bit prescaler. A 16-bit timer can also be configured for event
capture or Pulse Width Modulation (PWM) generation.
Watchdog Timer (Section 10 on page 173)
A watchdog timer can generate nonmaskable interrupts (NMIs) or a reset when a time-out value is
reached. The watchdog timer is used to regain control when a system has failed due to a software
error or to the failure of an external device to respond in the expected way.
The Stellaris Watchdog Timer module consists of a 32-bit down counter, a programmable load
register, interrupt generation logic, and a locking register.
The Watchdog Timer can be configured to generate an interrupt to the controller on its first
time-out, and to generate a reset signal on its second time-out. Once the Watchdog Timer has
been configured, the lock register can be written to prevent the timer configuration from being
inadvertently altered.
Memory Peripherals
The Stellaris controllers offer both SRAM and Flash memory.
SRAM (Section 7.2.1 on page 89)
The LM3S310 static random access memory (SRAM) controller supports 4 KB SRAM. The
internal SRAM of the Stellaris devices is located at address 0x20000000 of the device memory
map. To reduce the number of time consuming read-modify-write (RMW) operations, ARM has
Preliminary
July 5, 2006