S3C8245/P8245/C8249/P8249 8-BIT TIMER A/B
11-5
8-BIT TIMER B

OVERVIEW

The S3C8245/C8249 micro-controller has an 8-bit counter called timer B. Timer B, which can be used to generate

the carrier frequency of a remote controller signal.

Pending condition of timer B is cleared automatically by hardware.

Timer B has two functions:

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

—To supply a clock source to the 16-bit timer/counter module, timer 0, for generating the timer 0 overflow interrupt.

8-bit
Down Counter
Timer B Data
High Byte Register
MUX
TBCON.0
(TBOF) To Other Block
(P3.0/TBPWM)
IRQ1
(TBINT)INT.GEN
TBCON.3
Repeat Control
Interrupt Control
M
U
X
f
XX
/1
f
XX
/2
f
XX
/4
f
XX
/8
TBCON.6-.7 TBCON.2
Timer B Data
Low Byte Register
CLK
TBCON.4-.5
Data Bus
8
NOTES:
1. The value of the TBDATAL register is loaded into the 8-bit counter when the operation of the timer B starts.
If a borrow occurs in the counter, the value of the TBDATAH register is loaded into the 8-bit counter.
However, if the next borrow occurs, the value of the TBDATAL register is loaded into the 8-bit counter.
2. Timer B input clock must be slower than CPU clock.

Figure 11-3. Timer B Functional Block Diagram