101
CHAPTER 6 8-BIT TIMER/EVENT COUNTERS 50 TO 53
User’s Manual U15104EJ2V0UD
6.3 Registers Controlling 8-Bit Timer/Event Counters 50 to 53
The following two types of registers control the 8-bit timer/event counters 50 to 53.
• Timer clock select registers 50 to 53 (TCL50 to TCL53)
• 8-bit timer mode control registers 50 to 53 (TMC50 to TMC53)
(1) Timer clock select registers 50 to 52 (TCL50 to TCL52)
These registers select the count clock of 8-bit timer counter 5n (TM5n) and the valid edge of the TI5n input.
TCL5n is set with an 8-bit memory manipulation instruction.
Reset input clears TCL50 to TCL52 to 00H.
Remark
n = 0 to 2
Figure 6-5. Format of Timer Clock Select Registers 50 to 52 (TCL50 to TCL52)
TCL5n2 TCL5n1 TCL5n0
Count clock selection
0
0
0
Falling edge of TI5n
0
0
1
Rising edge of TI5n
0
1
0
f
X
/2
(2.25 MHz)
0
1
1
f
X
/2
3
(563 kHz)
1
0
0
f
X
/2
5
(141 kHz)
1
0
1
f
X
/2
7
(35.2 kHz)
1
1
0
f
X
/2
9
(8.79 kHz)
1
1
1
f
X
/2
11
(2.20 kHz)
Cautions 1. Before changing the data of TCL5n, be sure to stop the timer operation.
2. Be sure to set bits 3 to 7 to 0.
Remarks 1. In the cascade mode, the setting of bits TCL50 or TCL52 of the lower timer (TM50 or TM52)
is valid, and the setting of bits TCL51 or TCL53 of the higher timer (TM51 or TM53) is invalid.
2. n = 0 to 2
3. f
X
: System clock oscillation frequency
4. ( ): f
X
= 4.5 MHz
7
6
5
4
3
0
0
0
TCL502 TCL501 TCL500
0
0
2
1
0
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
Symbol
TCL50
Address
FF84H
After reset
00H
R/W
R/W
0
0
0
TCL512 TCL511 TCL510
0
0
TCL51
FF87H
00H
R/W
0
0
0
TCL522 TCL521 TCL520
0
0
TCL52
FF74H
00H
R/W
Содержание mPD178053
Страница 2: ...2 User s Manual U15104EJ2V0UD MEMO ...