CHAPTER 6 16-BIT TIMER
6.4.5 Buzzer output operation
The buzzer frequency is set using buzzer output control register 90 (BZC90) based on the count clock selected
with TCL901 and TCL900 of TMC90 (source clock). A square wave of the set buzzer frequency is output.
Table 6-4 shows the buzzer frequency.
Set the 16-bit timer as follows to use it for buzzer output:
• Set P21 to output mode (PM21 = 0).
• Reset output latch of P21 to 0.
• Set a count clock using TCL901 and TCL900.
• Set BZC90 as shown in Figure 6-12.
Figure 6-12. Settings of Buzzer Output Control Register 90 for Buzzer Output Operation
BCS902 BCS901 BCS900 BZOE90
BZC90
0
0
0
0
0/1
0/1
0/1
1
Enables buzzer output
Setting of buzzer frequency (see Table 6-4)
Table 6-4. Buzzer Frequency of 16-Bit Timer
BCS902
BCS901
BCS900
Buzzer Frequency
fcl = fX/22
fcl/24 (78.1 kHz)
fcl/25 (39.1 kHz)
fcl/28 (4.88 kHz)
fcl/29 (2.44 kHz)
fcl/210 (1.22 kHz)
fcl/211 (610 Hz)
fcl/212 (305 Hz)
fcl/213 (153 Hz)
fcl = fX/26
fcl/24 (4.88 kHz)
fcl/25 (2.44 kHz)
fcl/28 (305 Hz)
fcl/29 (153 Hz)
fcl/210 (76 Hz)
fcl/211 (38 Hz)
fcl/212 (19 Hz)
fcl/213 (10 Hz)
fcl = fX/27
fcl/24 (2.44 kHz)
fcl/25 (1.22 kHz)
fcl/28 (153 Hz)
fcl/29 (76 Hz)
fcl/210 (38 Hz)
fcl/211 (19 Hz)
fcl/212 (10 Hz)
fcl/213 (5 Hz)
fcl = fXT
fcl/24 (2.05 kHz)
fcl/25 (1.02 kHz)
fcl/28 (128 Hz)
fcl/29 (64 Hz)
fcl/210 (32 Hz)
fcl/211 (16 Hz)
fcl/212 (8 Hz)
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
fcl/213 (4 Hz)
Remarks 1. fX: Main system clock oscillation frequency
2. fXT: Subsystem clock oscillation frequency
3. The parenthesized values apply to operation at fX = 5.0 MHz or fXT = 32.768 kHz.
User’s Manual U15075EJ1V0UM00
128
NEC [ NEC ]
