Datasheet

78K0/Ix2 CHAPTER 8 8-BIT TIMER/EVENT COUNTER 51
R01UH0010EJ0500 Rev.5.00 324
Feb 28, 2012
Figure 8-1. Block Diagram of 8-Bit Timer/Event Counter 51
3
TCL512 TCL511 TCL510
TCE51
INTTM51
fPRS/2
4
fPRS/2
6
fPRS/2
8
8-bit timer H1 output
f
PRS/2
Internal bus
8-bit timer compare
register 51 (CR51)
Match
Mask circuit
8-bit timer
counter 51 (TM51)
Selector
Clear
Timer clock selection
register 51 (TCL51)
Internal bus
8-bit timer mode control
register 51 (TMC51)
TI51/P30/
TOH1/INTP1
fPRS
Remarks 1. 78K0/IY2 : <TI51>/P34/TOX11/<TOH1>/INTP4
78K0/IA2, 78K0/IB2 (32 pins) : <TI51>/P34/TOX11/<TOH1>/INTP4, <TI51>/P00/TI000/<TOH1>/INTP0
78K0/IB2 (30 pins) : TI51/P30/TOH1/INTP1
2. Functions in angle brackets < > can be assigned by setting the input switch control register (MUXSEL)
(1) 8-bit timer counter 51 (TM51)
TM51 is an 8-bit register that counts the count pulses and is read-only.
The counter is incremented in synchronization with the rising edge of the count clock.
Figure 8-2. Format of 8-Bit Timer Counter 51 (TM51)
Symbol
TM51
Address: FF1FH After reset: 00H R
In the following situations, the count value is cleared to 00H.
<1> Reset signal generation
<2> When TCE51 is cleared
<3> When TM51 and CR51 match