Information

System Configuration

MPC8308 PowerQUICC II Pro Processor Reference Manual, Rev. 1

5-56 Freescale Semiconductor

• Reset reference mode. The corresponding timer count is reset immediately after the reference value

is reached.

5.6.3.4 Capture Modes

Each timer has a 16-bit field in GTCPR, used to latch the value of the counter when a defined transition of

TINx is sensed by the corresponding input capture edge detector.

• Normal gate mode enables the count on a falling edge of the TGATE pin and disables the count on

the rising edge of TGATE. This mode allows the timer to count conditionally, based on the state of

TGATE.

• The restart gate mode performs the same function as normal mode, except it also resets the counter

on the falling edge of the TGATE pin. This mode has applications in pulse interval measurement

and bus monitoring.

5.6.4 GTM External Signal Description

This section provides an overview and detailed descriptions of the GTM signals.

There are four distinct external input timer capture signals (TIN1, TIN2, TIN3, and TIN4), four distinct

external input timer gate signals (TGATE1, TGATE2, TGATE3, and TGATE4), and four distinct external

timer output signals (TOUT1, TOUT2, TOUT3, and TOUT4). The GTM interface signals are defined in

Table 5-53.

Table 5-53. GTM Signal Properties

Name Port Function I/O Reset

Require

Pull Up

TIN1 TIN1 Global timer 1 capture control signal I 0 No

TIN2 TIN2 Global timer 2 capture control signal I 0 No

TIN3 TIN3 Global timer 3 capture control signal I 0 No

TIN4 TIN4 Global timer 4 capture control signal I 0 No

TGATE1

TGATE1 Global timer 1 counter gate control signal I 0 No

TGATE2 TGATE2 Global timer 2 counter gate control signal I 0 No

TGATE3 TGATE3 Global timer 3 counter gate control signal I 0 No

TGATE4 TGATE4 Global timer 4 counter gate control signal I 0 No

TOUT1 TOUT1 Global timer 1 counter output signal O 1 No

TOUT2 TOUT2 Global timer 2 counter output signal O 1 No

TOUT3 TOUT3 Global timer 3 counter output signal O 1 No

TOUT4 TOUT4 Global timer 4 counter output signal O 1 No