Instruction Manual

Preliminary W79E8213/W79E8213R Data Sheet
Publication Release Date: July 11, 2008
- 19 - Revision A2
BIT NAME FUNCTION
7 TF1
Timer 1 Overflow Flag. This bit is set when Timer 1 overflows. It is cleared
automatically when the program does a timer 1 interrupt service routine. Software
can also set or clear this bit.
6 TR1
Timer 1 Run Control. This bit is set or cleared by software to turn timer/counter on
or off.
5 TF0
Timer 0 Overflow Flag. This bit is set when Timer 0 overflows. It is cleared
automatically when the program does a timer 0 interrupt service routine. Software
can also set or clear this bit.
4 TR0
Timer 0 Run Control. This bit is set or cleared by software to turn timer/counter on
or off.
3 IE1
Interrupt 1 Edge Detect Flag: Set by hardware when an edge/level is detected on
INT1
. This bit is cleared by hardware when the service routine is vectored to only if
the interrupt was edge triggered. Otherwise it follows the inverse of the pin.
2 IT1
Interrupt 1 Type Control. Set/cleared by software to specify falling edge/ low level
triggered external inputs.
1 IE0
Interrupt 0 Edge Detect Flag. Set by hardware when an edge/level is detected on
INT0
. This bit is cleared by hardware when the service routine is vectored to only if
the interrupt was edge triggered. Otherwise it follows the inverse of the pin.
0 IT0
Interrupt 0 Type Control: Set/cleared by software to specify falling edge/ low level
triggered external inputs.
TIMER MODE CONTROL
Bit: 7 6 5 4 3 2 1 0
GATE
TC/
M1 M0 GATE
TC/
M1 M0
TIMER1 TIMER0
Mnemonic: TMOD Address: 89h
BIT NAME FUNCTION
7 GATE
Gating control: When this bit is set, Timer/counter 1 is enabled only while the
INT1
pin is high and the TR1 control bit is set. When cleared, the
INT1 pin has no effect,
and Timer 1 is enabled whenever TR1 control bit is set.
6
TC/
Timer or Counter Select: When clear, Timer 1 is incremented by the internal clock.
When set, the timer counts falling edges on the T1 pin.
5 M1 Timer 1 mode select bit 1. See table below.
4 M0 Timer 1 mode select bit 0. See table below.
3 GATE
Gating control: When this bit is set, Timer/counter 0 is enabled only while the
INT0
pin is high and the TR0 control bit is set. When cleared, the
INT0 pin has no effect,
and Timer 0 is enabled whenever TR0 control bit is set.
2
TC/
Timer or Counter Select: When clear, Timer 0 is incremented by the internal clock.
When set, the timer counts falling edges on the T0 pin.
1 M1 Timer 0 mode select bit 1. See table below.
0 M0 Timer 0 mode select bit 0. See table below.
M1, M0: Mode Select bits: