Rainbow Electronics AT89LP216 - Manual (Page 31)

31
3621A–MICRO–6/06
AT89LP216 [Preliminary]
Table 14-2. TMOD: Timer/Counter Mode Control Register
TMOD = 88H Reset Value = 0000 0000B
Not Bit Addressable
GATE C/T M1 M0 GATE C/T M1 M0
7 6 5 4 3 2 1 0
Timer1 Timer0
Gate Gating control when set. Timer/Counter x is enabled only
while INTx pin is high and TRx control pin is set. When
cleared, Timer x is enabled whenever TRx control bit
is set. Timer 0 gate bit
C/T Timer or Counter Selector cleared for Timer operation
(input from internal system clock). Set for Counter
operation (input from Tx input pin). Timer 0 counter/timer select bit
M1 Timer 1 Mode bit 1 Timer 0 M1 bit
M0 Timer 1 Mode bit 0 Timer 0 M0 bit
M1 M0 Mode Operating Mode
0 0 0 Variable 9 - 16-bit Timer Mode.
8-bit Timer/Counter THx with TLx as 1 - 8-bit prescaler.
0 1 1 16-bit Auto-Reload Mode.
16-bit Timer/Counters THx and TLx are cascaded; there is no prescaler.
1 0 2 8-bit Auto Reload.
8-bit auto-reload Timer/Counter THx holds a value which is to be
reloaded into TLx each time it overflows.
1 1 3 Split Timer Mode.
(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.
1 1 3 (Timer 1) Timer/Counter 1 stopped.
Timer SFR Purpose Address Bit-Addressable
TCON Control 88H Yes
TMOD Mode 89H No
TL0 Timer 0 low-byte 8AH No
TL1 Timer 1 low-byte 8BH No
TH0 Timer 0 high-byte 8CH No
TH1 Timer 1 high-byte 8DH No
TCONB Mode 91H No
RL0 Timer 0 reload low-byte 92H No
RL1 Timer 1 reload low-byte 93H No
RH0 Timer 0 reload high-byte 94H No
RH1 Timer 1 reload high-byte 95H No