Buzzer Output Pin; Figure 9.3-1 Block Diagram Of P37/Bz/(Rco) Pin - Fujitsu F2MC-8L Series Hardware Manual

9.3

Buzzer Output Pin

This section describes the pin and pin block diagram of the buzzer output.
Buzzer Output Pin
The buzzer output uses the P37/BZ/(RCO) pin.
P37/BZ/(RCO) pin
The P37/BZ/(RCO) pin serves as a general-purpose I/O port pin (P37), remote-control
transmission frequency output pin (RCO), or as buzzer output pin (BZ).
BZ:
This pin outputs a buzzer square wave with the specified frequency.
Setting a buzzer output frequency in the buzzer output register (BZCR: BZ2, BZ1, BZ0 =
other than "000
output latch value and the setting for the remote-control transmission frequency generator.
Block Diagram of Buzzer Output Pin
PDR
PDR read
PDR read
(for bit manipulation instructions)
PDR write
DDR write
SPL: Pin state specification bit in the standby control register (STBC)
Items enclosed in ( ) are applicable only to the MB89120A series.
Tip:
Pins with a pull-up resistor (optional) go to the "H" level during a reset or in stop or watch
mode (SPL = "1").
") automatically sets the P37/BZ/(RCO) pin as the BZ pin regardless of the
B

Figure 9.3-1 Block Diagram of P37/BZ/(RCO) Pin

Remote-control
transmission
frequency output
(Port data register)
Output latch
DDR
(Port data direction register)
Stop or watch mode (SPL=1)
MB89120A series only
Remote-control transmission
frequency output enable signal
To peripheral input
From buzzer output
From Buzzer
output enable
9.3 Buzzer Output Pin
Pull-up resistor
(optional)
Approx. 50 k
Stop or watch mode
(SPL=1)
Input buffer
P-ch
N-ch P37/BZ/(RCO)
/5.0 V
P-ch
Pin
223