Timer/Counter
MPC82x54A has two 16-bit timers, and they are named T0 and T1. Each of them can also be
used as a general event counter, which counts the transition from 1 to 0.
Since the MPC82x54A is a RISC-like MCU which executes faster than traditional 80C51 MCU
from other providers. Based on consideration of compatibility with traditional 80C51 MCUs,
the frequency of the clock source for T0 and T1 is designed to be selectable between
oscillator frequency divided-by-12 (default) or oscillator frequency.
The user can configure T0/T1 to work under mode-0, mode-1, mode-2 and mode-3. It is
entirely identical to the traditional 80C51 MCU.
There are two SFR designed to configure timers T0 and T1. They are TMOD, and TCON.
The user also should take a glance of SFR AUXR which determine the frequency of the clock
source driving the T0 and T1.
SFR: TMOD (Timer Mode Control Register)
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
GATE
C//T
M1
M0
GATE
C//T
M1
M0
(for timer1 use)
(for timer0 use)
GATE: = Gating control
0:= (default)
Timer x is enabled whenever “TRx” control bit is set.
1:=
Timer/Counter x is enabled only while “/INTx” pin is high and “TRx” control bit is set.
C//T: = Timer or Counter function selector. 0: =timer, 1: =counter
0:= (default)
Configure Tx as Timer use
1:=
Configure Tx as Counter use
{M1, M0}: mode select
{0, 0}: =
Configure Tx as 13-bit timer/counter
{0, 1}: =
Configure Tx as 16-bit timer/counter
{1, 0}: =
Configure Tx as 8-bit timer/counter with automatic reload capability
{1, 1}: =
for T0, set TL0 as 8-bit timer/counter, TH0 is locked into 8-bit timer
for T1, set Timer/Counter1 Stopped
24
MPC82x54A Data Sheet
MEGAWIN
MEGAWIN [ MEGAWIN TECHNOLOGY CO., LTD ]
