
1999 Oct 27
22
Philips Semiconductors
Preliminary specication
Standard TV microcontrollers with
On-Screen Display (OSD)
SAA55xx
Timer/Counter Control Register (TCON)
TF1
Timer 1 overow ag. Set by hardware on timer/counter overow. Cleared by
hardware when processor vectors to interrupt routine.
TR1
Timer 1 run control bit. Set/cleared by software to turn timer/counter on/off.
TF0
Timer 0 overow ag. Set by hardware on timer/counter overow. Cleared by
hardware when processor vectors to interrupt routine.
TR0
Timer 0 run control bit. Set/cleared by software to turn timer/counter on/off.
IE1
Interrupt 1 Edge ag. Both edges generate ag. Set by hardware when external
interrupt edge detected. Cleared by hardware when interrupt processed.
IT1
Interrupt 1 type control bit. Set/cleared by software to specify edge/LOW level
triggered external interrupts.
IE0
Interrupt 0 Edge l ag. Set by hardware when external interrupt edge detected.
Cleared by hardware when interrupt processed.
IT0
Interrupt 0 type ag. Set/cleared by software to specify falling edge/LOW level
triggered external interrupts.
14-bit PWM MSB Register (TDACH)
TPWE
activate this 14-bit PWM (logic 1)
TD13 to TD8
6 MSBs of 14-bit number to be output by the 14-bit PWM
14-bit PWM LSB Register (TDACL)
TD7 to TD0
8 LSBs of 14-bit number to be output by the 14-bit PWM
Timer 0 High byte (TH0)
TH07 to TH00
8 MSBs of Timer 0 16-bit counter
Timer 1 High byte (TH1)
TH17 to TH10
8 MSBs of Timer 1 16-bit counter
Timer 0 Low byte (TL0)
TL07 to TL00
8 LSBs of Timer 0 16-bit counter
Timer 1 Low byte (TL1)
TL17 to TL10
8 LSBs of Timer 1 16-bit counter
Timer/Counter Mode Control (TMOD)
GATE
gating control Timer/Counter 1
C/T
Counter/Timer 1 selector
M1 to M0
mode control bits timer/counter 1; M<1:0>:
00 = 8-bit timer or 8-bit counter with divide-by-32 prescaler
01 = 16-bit time interval or event counter
10 = 8-bit time interval or event counter with automatic reload upon overflow;
reload value stored in TH1
11 = stopped
GATE
Gating control Timer/Counter 0
C/T
Counter/Timer 0 selector
BIT
FUNCTION