MPC89L515A Megawin Technology, MPC89L515A Datasheet - Page 13

• Manufacturer Part Number: MPC89L515A
• Description: 8-bit micro-controller
• Manufacturer: Megawin Technology

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Functional Description
TIMERS/COUNTERS
MPC89x515A has three 16-bit timers, and they are named T0, T1 and T2. Each of them can also
be used as a general event counter, which counts the transition from 1 to 0.
While T0/T1/T2 is used as “timer” function, the time unit that used to measure the timer is machine
cycle. A machine cycle equals 12 or 6 oscillator periods, and it depends on 12T mode or 6T mode
that the user configured this device.
While T0/T1/T2 is used as “1-0 event counter” function, the counting event is the “high-to-low
transition” of primitive pin T0/T1/T2. In this mode, the device periodically samples the status of pin
T0/T1/T2 once for each machine cycle. Whenever the sampled result turns from 1 to 0, the device
will count once on the counter. Becarefully, this kind of implementation for the counter requires
the high-duty or low-duty from pin T0/T1/T2 and must not too short compared to a machine cycle.
There are two SFR designed to configure timers T0 and T1. They are TMOD, and TCON.
There are extra two SFR designed to configure timer T2. They are T2MOD, and T2CON.
SFR: TMOD
GATE: Gating control when set. If GATE=1, Timer/Counter x is enabled only while “/INTx” pin is high and
C//T: Timer or Counter function selector. 0: =timer, 1: =counter
{M1, M0}: mode select
MEGAWIN
GATE
Bit-7
“TRx” control bit is set. When cleared Timer x is enabled whenever “TRx” control bit is set.
{0, 0}: = 13-bit timer/counter for Timer0 and Timer1
{0, 1}: = 16-bit timer/counter for Timer0 and Timer1
{1, 0}: = 8-bit timer/counter with automatic reload for Timer0 and Timer1
{1, 1}: = for Timer0: = TL0 is 8-bit timer/counter, TH0 is locked into 8-bit timer
(for timer1 use)
Bit-6
C//T
for Timer1:= Timer/Counter1 Stopped
Bit-5
M1
Bit-4
M0
MPC89x515A Data Sheet
GATE
Bit-3
(for timer0 use)
Bit-2
C//T
Bit-1
M1
Bit-0
M0
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