Countdown timer in hardware instead of η-controller using

[idoa]

Hi,
I'm making a project for my electronics studies.
The project contains 4× 4 keyboard 4×20 LCD - for UI.
The Micro Controller that in use is: Silicon Lab. C8051F020.
The user should enter 3 to 1 numbers to countdown -A Timer. The counting is on 3 7-seg display and not on the LCD.
During the counting-down on the LCD will be instruction like: Press A for hold B for stop C for reset and stuff like that.

My problem is to make the count. The last thing I want is to use the TIMER INT in the 8051.
My question is:
Is there any component which has built-in osc. and can count-down.
Something like 14553B but to countdown and to behave like a real timer.

Thnks

 

[Ubergeek63]

why? are you afraid of interrupt routines? you could set up the timer and just poll the overflow flag, inefficient but workable.

The point is there is absolutely no reason for anyone to make such a component, the whole point of micros is that you no longer need special hardware.

Dan

 

[Mikebits]

From the 8051 data sheet.

Mode 3 is provided for applications requiring an extra 8-bit timer on
the counter. With Timer 0 in Mode 3, an 80C51 can look like it has
three Timer/Counters. When Timer 0 is in Mode 3, Timer 1 can be
turned on and off by switching it out of and into its own Mode 3, or
can still be used by the serial port as a baud rate generator, or in
fact, in any application not requiring an interrupt.