186
User’s Manual U11302EJ4V0UM
CHAPTER 11 BUZZER OUTPUT CONTROLLER
11.1 Buzzer Output Controller Functions
The buzzer output controller outputs a 1.2 kHz, 2.4 kHz, or 4.9 kHz frequency square-wave. The buzzer
frequency selected by timer clock select register 2 (TCL2) is output from the BUZ/P36 pin.
Follow the procedure below to output the buzzer frequency.
[1] Select the buzzer output frequency using bits 5 to 7 (TCL25 to TCL27) of TCL2.
[2] Set the P36 output latch to 0.
[3] Set bit 6 (PM36) of port mode register 3 (PM3) to 0 (set to output mode).
Caution
Buzzer output cannot be used when the P36 output latch is set to 1.
11.2 Buzzer Output Controller Configuration
The buzzer output controller consists of the following hardware.
Table 11-1. Buzzer Output Controller Configuration
Item
Configuration
Control registers
Timer clock select register 2 (TCL2)
Port mode register 3 (PM3)
Figure 11-1. Buzzer Output Controller Block Diagram
f
X
/2
10
f
X
/2
11
f
X
/2
12
P36
output
latch
3
BUZ/P36
PM36
TCL27TCL26TCL25
Internal bus
Timer clock select
register 2
Port mode register 3
Selector