P87LPC768 NXP Semiconductors, P87LPC768 Datasheet - Page 40

• Manufacturer Part Number: P87LPC768
• Description: The P87LPC768 is a 20-pin single-chip microcontroller designed forlow pin count applications demanding high-integration, low costsolutions over a wide range of performance requirements
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Mode 1
Mode 1 is the same as Mode 0, except that all 16 bits of the timer
register (THn and TLn) are used. See Figure 28
Mode 2
Mode 2 configures the Timer register as an 8-bit Counter (TL1) with
automatic reload, as shown in Figure 29. Overflow from TLn not only
sets TFn, but also reloads TLn with the contents of THn, which must
be preset by software. The reload leaves THn unchanged. Mode 2
operation is the same for Timer 0 and Timer 1.
Mode 3
When Timer 1 is in Mode 3 it is stopped. The effect is the same as
setting TR1 = 0.
2002 Mar 12
Low power, low price, low pin count (20 pin) microcontroller
with 4 kB OTP 8-bit A/D, Pulse Width Modulator
OSC/6
OSC/6
OSC/12
OSC/12
INTn PIN
INTn PIN
Tn PIN
Tn PIN
GATE
GATE
TRn
TRn
OR
OR
Figure 29. Timer/Counter 0 or 1 in Mode 2 (8-Bit Auto-Reload)
C/T = 1
C/T = 1
Figure 28. Timer/Counter 0 or 1 in Mode 1 (16-Bit Counter)
C/T = 0
C/T = 0
CONTROL
CONTROL
38
Timer 0 in Mode 3 establishes TL0 and TH0 as two separate 8-bit
counters. The logic for Mode 3 on Timer 0 is shown in Figure 30.
TL0 uses the Timer 0 control bits: C/T, GATE, TR0, INT0, and TF0.
TH0 is locked into a timer function (counting machine cycles) and
takes over the use of TR1 and TF1 from Timer 1. Thus, TH0 now
controls the “Timer 1” interrupt.
Mode 3 is provided for applications that require an extra 8-bit timer.
With Timer 0 in Mode 3, an P87LPC768 can look like it has three
Timer/Counters. When Timer 0 is in Mode 3, Timer 1 can be turned
on and off by switching it into and out of its own Mode 3. It can still
be used by the serial port as a baud rate generator, or in any
application not requiring an interrupt.
(8-BITS)
(8-BITS)
(8 BITS)
THN
TLN
TLn
RELOAD
(8 BITS)
THn
OVERFLOW
TOGGLE
TOGGLE
OVERFLOW
TnOE
TnOE
TFn
TFn
P87LPC768
INTERRUPT
Tn PIN
INTERRUPT
Preliminary data
Tn PIN
SU01174
SU01175