71M6403 Datasheet, PDF (25/75 Pages) Teridian Semiconductor Corporation – Electronic Trip Unit

71M6403
Electronic Trip Unit
SEPTEMBER 2006
M1
M0
Mode Function
0
0
Mode 0 13-bit Counter/Timer with 5 lower bits in the TL0 or TL1 register and the
remaining 8 bits in the TH0 or TH1 register (for Timer 0 and Timer 1,
respectively). The 3 high order bits of TL0 and TL1 are held at zero.
0
1
Mode 1 16-bit Counter/Timer.
1
0
Mode2 8-bit auto-reload Counter/Timer. The reload value is kept in TH0 or TH1,
while TL0 or TL1 is incremented every machine cycle. When TL(x)
overflows, a value from TH(x) is copied to TL(x).
1
1
Mode3 If Timer 1 M1 and M0 bits are set to '1', Timer 1 stops. If Timer 0 M1 and M0
bits are set to '1', Timer 0 acts as two independent 8-bit Timer/Counters.
Note:
Table 19: Timers/Counters Mode Description
TL0 is affected by TR0 and gate control bits, and sets TF0 flag on overflow.
TH0 is affected by TR1 bit, and sets TF1 flag on overflow.
Timer/Counter Control Register (TCON)
MSB
TF1
TR1
TF0
TR0
IE1
IT1
IE0
Table 20: The TCON Register
LSB
IT0
Bit
TCON.7
TCON.6
TCON.5
TCON.4
TCON.3
TCON.2
TCON.1
TCON.0
Symbol
TF1
TR1
TF0
TR0
IE1
IT1
IE0
IT0
Function
The Timer 1 overflow flag is set by hardware when Timer 1 overflows. This flag
can be cleared by software and is automatically cleared when an interrupt is
processed.
Timer 1 Run control bit. If cleared, Timer 1 stops.
Timer 0 overflow flag set by hardware when Timer 0 overflows. This flag can be
cleared by software and is automatically cleared when an interrupt is processed.
Timer 0 Run control bit. If cleared, Timer 0 stops.
Interrupt 1 edge flag is set by hardware when the falling edge on external pin
int1 is observed. Cleared when an interrupt is processed.
Interrupt 1 type control bit. Selects either the falling edge or low level on input
pin to cause an interrupt.
Interrupt 0 edge flag is set by hardware when the falling edge on external pin
int0 is observed. Cleared when an interrupt is processed.
Interrupt 0 type control bit. Selects either the falling edge or low level on input
pin to cause interrupt.
Table 21: The TCON Register Bit Functions
Page: 25 of 75
© 2006 TERIDIAN Semiconductor Corporation
REV 1.0