Datasheet

FS98O22
Rev. 1.6 84/146
7.6. Digital I/O Port or Buzzer Output : PT2[7]
Figure 7-6 PT2[7] function block
GPIO Port 2 Bit2 (PT2[2]) function block is shown in Figure 7-6. The main function of the GPIO is input and
output data between the Data bus and the ports. Users could control the PT2EN[2] register flags to decide the
input output direction. The input and output function and the related functions are explained as follows:
z Input:
GPIO Port 2 Bit2 (PT1[2]) could be the Buzzer output port or be the general I/O port. User should setup
BZEN register flag to decide if the Buzzer output is enabled. The detailed Buzzer usage is described in
Section 5.4.
z Output
FS98O22 sends the digital data out by an embedded D Flip Flop. When the program sends data out
through PT2, the data will be sent to data bus first, and then the D Flip Flop will latch the signal for PT2
output while the Write signal and AR (FS98O22 internal device address pointer) is pointed to PT2.
z Pull up resistor
FS98O22 embeds an internal pull up resistor function in PT2 with about 1000k ohm resistor
20
. User could
control the PT2PU[2] register flags to set the connection to pull up resistor. When a port is connected to
the pull up resistor, the input data is, by default, assigned to high (data 1).
20
The pull up current is about 10uA. Remember to disable PT1PU before program falls into Sleep mode.
FORTUNE'
Properties
For Reference Only