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Preliminary Product Information
42
μ
PD789186, 789187, 789196, 789197
(2) Buzzer output control register (BZC90)
This register outputs square waves with frequencies of 1.25 MHz, 78.125 kHz, 39.063 kHz, and 32.768 kHz.
Based on an fcl frequency selected with the count clock selection registers (TCL901, TCL900), a buzzer
frequency selected with the buzzer output control register (BZC90) is output on the BZO90/INTP3/TO82/P33.
BZC90 is manipulated using a 1-bit or 8-bit memory manipulation instruction.
A RESET input clears BZC90 to 00H.
Figure 6-13. Format of Buzzer Output Control Register
BZOE90
Buzzer port output control
Disables buzzer port output.
Enables buzzer port output.
Note 2
0
1
0
0
0
0
BCS902
BCS901
BCS900
BZOE90
BZC90
Symbol
Address
When reset
R/W
FF49H
00H
R/W
6
7
5
4
BCS902
BCS901
BCS900
Buzzer frequency
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
1
1
0
1
3
2
1
0
fcl = f
X
/2
2
fcl = f
X
/2
6
fcl = f
X
/2
7
fcl = f
XT
fcl/2
4
(78.125 kHz)
fcl/2
5
(39.063 kHz)
fcl/2
8
(4883 Hz)
fcl/2
9
(2441 Hz)
fcl/2
10
(1221 Hz)
fcl/2
11
(610 Hz)
fcl/2
12
(305 Hz)
fcl/2
13
(153 Hz)
fcl/2
4
(4883 Hz)
fcl/2
5
(2441 Hz)
fcl/2
8
(305 Hz)
fcl/2
9
(153 Hz)
fcl/2
10
(76 Hz)
fcl/2
11
(38 Hz)
fcl/2
12
(19 Hz)
fcl/2
13
(10 Hz)
fcl/2
4
(2441 Hz)
fcl/2
5
(1221 Hz)
fcl/2
8
(153 Hz)
fcl/2
9
(76 Hz)
fcl/2
10
(38 Hz)
fcl/2
11
(19 Hz)
fcl/2
12
(10 Hz)
fcl/2
13
(5 Hz)
fcl/2
4
(2048 Hz)
fcl/2
5
(1024 Hz)
fcl/2
8
(128 Hz)
fcl/2
9
(64 Hz)
fcl/2
10
(32 Hz)
fcl/2
11
(16 Hz)
fcl/2
12
(8 Hz)
fcl/2
13
(4 Hz)
Note 1
Notes 1.
Bits 4 to 7 must be fixed to 0.
2.
When setting BZOE90 to 1, TOE82 must be fixed to 0. (See
Figure 6-20
.)
Caution
If the subclock is selected as the count clock (TCL901 = 1, TCL900 = 1: Figure 6-12), the
subclock is not synchronized when buzzer port output is enabled. In this case, the capture
function and TM90 register read function are disabled. In addition, the count value of the TM90
register is undefined.
Remarks 1.
f
X
: Main system clock frequency
2.
f
XT
: Subsystem clock frequency
3.
The parenthesized values apply to operation at f
X
= 5.0 MHz.