LM3S6100 Datasheet, PDF (289/559 Pages) Texas Instruments – Stellaris® LM3S6100 Microcontroller

Stellaris^® LM3S6100 Microcontroller
Table 8-2. General-Purpose Timers Signals (100LQFP) (continued)
Pin Name
Pin Number Pin Type Buffer Type^a Description
CCP2
67
I/O
TTL
Capture/Compare/PWM 2.
CCP3
23
I/O
TTL
Capture/Compare/PWM 3.
a. The TTL designation indicates the pin has TTL-compatible voltage levels.
Table 8-3. General-Purpose Timers Signals (108BGA)
Pin Name
Pin Number Pin Type Buffer Type^a Description
CCP0
E12
I/O
TTL
Capture/Compare/PWM 0.
CCP1
L6
I/O
TTL
Capture/Compare/PWM 1.
CCP2
D12
I/O
TTL
Capture/Compare/PWM 2.
CCP3
M2
I/O
TTL
Capture/Compare/PWM 3.
a. The TTL designation indicates the pin has TTL-compatible voltage levels.
8.3 Functional Description
The main components of each GPTM block are two free-running 16-bit up/down counters (referred
to as TimerA and TimerB), two 16-bit match registers, two prescaler match registers, and two 16-bit
load/initialization registers and their associated control functions. The exact functionality of each
GPTM is controlled by software and configured through the register interface.
Software configures the GPTM using the GPTM Configuration (GPTMCFG) register (see page 299),
the GPTM TimerA Mode (GPTMTAMR) register (see page 300), and the GPTM TimerB Mode
(GPTMTBMR) register (see page 302). When in one of the 32-bit modes, the timer can only act as
a 32-bit timer. However, when configured in 16-bit mode, the GPTM can have its two 16-bit timers
configured in any combination of the 16-bit modes.
8.3.1
GPTM Reset Conditions
After reset has been applied to the GPTM module, the module is in an inactive state, and all control
registers are cleared and in their default states. Counters TimerA and TimerB are initialized to
0xFFFF, along with their corresponding load registers: the GPTM TimerA Interval Load
(GPTMTAILR) register (see page 313) and the GPTM TimerB Interval Load (GPTMTBILR) register
(see page 314). The prescale counters are initialized to 0x00: the GPTM TimerA Prescale
(GPTMTAPR) register (see page 317) and the GPTM TimerB Prescale (GPTMTBPR) register (see
page 318).
8.3.2
32-Bit Timer Operating Modes
This section describes the three GPTM 32-bit timer modes (One-Shot, Periodic, and RTC) and their
configuration.
The GPTM is placed into 32-bit mode by writing a 0 (One-Shot/Periodic 32-bit timer mode) or a 1
(RTC mode) to the GPTM Configuration (GPTMCFG) register. In both configurations, certain GPTM
registers are concatenated to form pseudo 32-bit registers. These registers include:
■ GPTM TimerA Interval Load (GPTMTAILR) register [15:0], see page 313
■ GPTM TimerB Interval Load (GPTMTBILR) register [15:0], see page 314
■ GPTM TimerA (GPTMTAR) register [15:0], see page 321
■ GPTM TimerB (GPTMTBR) register [15:0], see page 322
June 18, 2012
289
Texas Instruments-Production Data