Samsung S3C84E5 user manual BIT Timer B, 11-5

S3C84E5/C84E9/P84E9 8-BIT TIMER A/B

8-BIT TIMER B

OVERVIEW

The S3C84E5/C84E9/P84E9 micro-controller has an 8-bit timer called timer B. Timer B, which can be used to generate the carrier frequency of a remote controller signal. Also, it can be used as the programmable buzz signal generator that makes a sound with a various frequency from 200Hz to 20kHz. These various frequencies can be used to generate a melody sound.

Timer B has two functions:

—As a normal interval timer, generating a timer B interrupt at programmed time intervals.

—To generate a programmable carrier pulse for a remote control signal at P4.3.

BLOCK DIAGRAM

TBCON.6-.7		TBCON.2	PG trigger signal
				TBCON.0
f xx/4	M
f xx/8		CLK	8-Bit	T-FF
	U
fxx/64			Down Counter	TB Underflow
	X
fxx/256				(TBUF)
				TBCON.3
TBCON.1		Repeat	MUX
		Control

TBPWM(P4.3)

TBINT

TBCON.4-.5

Timer B Data

Low Byte Register

8

Data Bus

Timer B Data

High Byte Register

8

Data Bus

NOTE: In case of setting TBCON.5-.4 at '10', the value of the TBDATAL register is loaded into the 8-bit counter when the operation of the timer B starts. And then if a underflow occurs

in the counter, the value of the TBDATAH register is loaded into the value of the 8-bit counter. However, if the next borrow occurs, the value of the TBDATAL register is loaded into the value of the 8-bit counter. To output TBPWM as carrier wave, you have to set P4CONL.7-.6 as "11".

Figure 11-3. Timer B Functional Block Diagram

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