P89V51RD2 Philips Semiconductors, P89V51RD2 Datasheet - Page 26

• Manufacturer Part Number: P89V51RD2
• Description: 8-bit 80C51 5 V low power 64 kB Flash microcontroller with 1 kB RAM
• Manufacturer: Philips Semiconductors

Philips Semiconductors
9397 750 12964
Product data
7.3.1 Mode 0
Table 14:
Table 15:
Bit addressable; Reset value: 00000000B; Reset source(s): any reset
Table 16:
Putting either Timer into Mode 0 makes it look like an 8048 Timer, which is an 8-bit
Counter with a fixed divide-by-32 prescaler.
M1
0
0
1
1
1
Bit
7
6
5
4
3
2
1
0
Bit
Symbol
TMOD - Timer/Counter mode control register (address 89H) M1/M0 operating
mode
TCON - Timer/Counter control register (address 88H) bit allocation
TCON - Timer/Counter control register (address 88H) bit description
Symbol
TF1
TR1
TF0
TR0
IE1
IT1
IE0
IT0
TF1
M0
0
1
0
1
1
7
Rev. 01 — 01 March 2004
TR1
6
Description
Timer 1 overflow flag. Set by hardware on Timer/Counter overflow.
Cleared by hardware when the processor vectors to Timer 1
Interrupt routine, or by software.
Timer 1 Run control bit. Set/cleared by software to turn
Timer/Counter 1 on/off.
Timer 0 overflow flag. Set by hardware on Timer/Counter overflow.
Cleared by hardware when the processor vectors to Timer 0
Interrupt routine, or by software.
Timer 0 Run control bit. Set/cleared by software to turn
Timer/Counter 0 on/off.
Interrupt 1 Edge flag. Set by hardware when external interrupt 1
edge/low level is detected. Cleared by hardware when the interrupt
is processed, or by software.
Interrupt 1 Type control bit. Set/cleared by software to specify
falling edge/low level that triggers external interrupt 1.
Interrupt 0 Edge flag. Set by hardware when external interrupt 0
edge/low level is detected. Cleared by hardware when the interrupt
is processed, or by software.
Interrupt 0 Type control bit. Set/cleared by software to specify
falling edge/low level that triggers external interrupt 0.
Operating mode
0
1
2
3
3
TF0
5
8048 timer ‘TLx’ serves as 5-bit prescaler
16-bit Timer/Counter ‘THx’ and ‘TLx' are
cascaded; there is no prescaler.
8-bit auto-reload Timer/Counter ‘THx’ holds a
value which is to be reloaded into ‘TLx’ each
time it overflows.
(Timer 0) TL0 is an 8-bit Timer/Counter
controlled by the standard Timer 0 control bits.
TH0 is an 8-bit timer only controlled by Timer 1
control bits.
(Timer 1) Timer/Counter 1 stopped.
TR0
4
8-bit microcontrollers with 80C51 core
Figure 7
IE1
3
shows Mode 0 operation.
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
P89V51RD2
IT1
2
IE0
1
26 of 75
IT0
0