Samsung S3F80JB manual Basic Timer BT

S3F80JB BASIC TIMER and TIMER 0

10 BASIC TIMER and TIMER 0

OVERVIEW

The S3F80JB has two default timers: the 8-bit basic timer and the 8-bit general-purpose timer/counter. The 8-bit timer/counter is called timer 0.

BASIC TIMER (BT)

You can use the basic timer (BT) in two different ways:

—As a watch-dog timer to provide an automatic reset mechanism in the event of a system malfunction

—To signal the end of the required oscillation stabilization interval after a reset or a Stop mode release.

The functional components of the basic timer block are:

—Clock frequency divider (fOSC divided by 4096, 1024 or 128) with multiplexer

—8-bit basic timer counter, BTCNT (FDH, Set 1, Bank0, Read-only)

—Basic timer control register, BTCON (D3H, Set 1, Bank0, R/W)

TIMER 0

Timer 0 has three operating modes, one of which you select using the appropriate T0CON setting:

—Interval timer mode

—Capture input mode with a rising or falling edge trigger at the P3.0 pin

—PWM mode

Timer 0 has the following functional components:

—Clock frequency divider (fOSC divided by 4096, 256 or 8) with multiplexer

—External clock input pin (T0CK)

—8-bit timer 0 counter (T0CNT), 8-bit comparator, and 8-bit reference data register (T0DATA)

—I/O pins for capture input (T0CAP) or match output

—Timer 0 overflow interrupt (IRQ0, vector FAH) and match/capture interrupt (IRQ0, vector FCH) generation

—Timer 0 control register, T0CON (D2H, Set 1, Bank0, R/W)

NOTE

The CPU clock should be faster than basic timer clock and timer 0 clock.

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