Datasheet

FS98O22

Rev. 1.6 82/146

7.5. Digital I/O Port : PT2[6]

Figure 7-5 PT2[6] function block

GPIO Port 2 Bit 6 (PT2[6]) function block is shown in Figure 7-5. The main function of the GPIO is input and

output data between the Data bus and the ports. Users could control the PT2EN[6] register flags to decide the

input output direction. The input and output function are explained as follows:

z Input:

GPIO Port 2 Bit 6 (PT2[6]) could only be the general I/O ports. The input port has a Schmitt trigger in it,

and the up/down trigger voltage level is 0.45VDD/0.2VDD.

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

. User could

control the PT2PU[6] register flags to set the connections 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).

The pull up current is about 10uA. Remember to disable PT1PU before program falls into Sleep mode.

FORTUNE'

Properties

For Reference Only