Rainbow Electronics T89C51CC02 - Manual (Page 52)

52 Rev.A - May 17, 2001
Preliminary
T89C51CC02
Figure 34. Timer/Counter x (x= 0 or 1) in Mode 0
12.3.2. Mode 1 (16-bit Timer)
Mode 1 configures Timer 0 as a 16-bit Timer with TH0 and TL0 registers connected in cascade (see Figure 35).
The selected input increments TL0 register.
Figure 35. Timer/Counter x (x= 0 or 1) in Mode 1
12.3.3. Mode 2 (8-bit Timer with Auto-Reload)
Mode 2 configures Timer 0 as an 8-bit Timer (TL0 register) that automatically reloads from TH0 register (see
Figure 36). TL0 overflow sets TF0 flag in TCON register and reloads TL0 with the contents of TH0, which is
preset by software. When the interrupt request is serviced, hardware clears TF0. The reload leaves TH0 unchanged.
The next reload value may be changed at any time by writing it to TH0 register.
Figure 36. Timer/Counter x (x= 0 or 1) in Mode 2
PERIPH
CLOCK
TRx
TCON reg
TFx
TCON reg
0
1
GATEx
TMOD reg
÷
6
Overflow
Timer x
Interrupt
Request
C/Tx#
TMOD reg
TLx
(5 bits)
THx
(8 bits)
INTx#
Tx
TRx
TCON reg
TFx
TCON reg
0
1
GATEx
TMOD reg
Overflow
Timer x
Interrupt
Request
C/Tx#
TMOD reg
TLx
(8 bits)
THx
(8 bits)
INTx#
Tx
PERIPH
CLOCK
÷
6
TRx
TCON reg
TFx
TCON reg
0
1
GATEx
TMOD reg
Overflow
Timer x
Interrupt
Request
C/Tx#
TMOD reg
TLx
(8 bits)
THx
(8 bits)
INTx#
Tx
PERIPH
CLOCK
ч
6