C/T2: Timer or counter select. 0 is for timer and 1 is for external event counter.

CP/RL2: Capture/Reload flag. When set, captures will occurs on a negative transition at T2EX if

EXEN2=1. When cleared, auto-reloads will occur either with Timer2 overflows or a negative

transition at T2EX when EXEN2=1. When whether TCLK or RCLK is 1, this bit is ignored and

the timer is forced to auto-reload on Timer2 overflow.

TIMER0 (T0) AND TIMER1 (T1)

Mode 0

The timer register is configured as a 13-bit register. As when the count rolls over from all 1s to

all 0s, it sets the timer interrupt flag TFx. The counted input is enabled to the timer when TRx =

1 and either GATE=0 or INTx = 1. Mode 0 operation is the same for Timer0 and Timer1.

Mode 0

0

1

OSC/12

T0 or T1 pin

(sampled)

0

1

GATE

/INTx

TRx

TLx[4:0] THx[7:0]

TFx

Interrupt

C//T

Mode 1

Mode1 is the same as Mode0, except that the timer register is being run with all 16 bits.

Mode 1

0

1

OSC/12

T0 or T1 pin

(sampled)

0

1

GATE

/INTx

TRx

TLx[7:0] THx[7:0]

TFx

Interrupt

C//T

Mode 2

Mode 2 configures the timer register as an 8-bit counter (TLx) with automatic reload. Overflow

from TLx does not only set TFx, but also reloads TLx with the content of THx, which is

determined by user’s program. The reload leaves THx unchanged. Mode 2 operation is the

same for Timer0 and Timer1.

MEGAWIN

MPC89x53A Data Sheet

15