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S3C8248/C8245/P8245/C8247/C8249/P8249
8-BIT TIMER B
OVERVIEW
The S3C8248/C8245/P8245 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.
TBCON.6-.7
f
/1
XX
M
f
/2
XX
U
f
/4
XX
f
/8
X
XX
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.
TBCON.2
CLK
Repeat Control
Interrupt Control
TBCON.4-.5
Figure 11-3. Timer B Functional Block Diagram
8-bit
Down Counter
MUX
Timer B Data
Low Byte Register
Timer B Data
High Byte Register
8
Data Bus
8-BIT TIMER A/B
TBCON.0
(TBOF)
TBCON.3
INT.GEN
To Other Block
(P3.0/TBPWM)
IRQ1
(TBINT)
11-5
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