Operation - Panasonic F77G User Manual

Chapter 4 I/O Ports
4-11-3

Operation

Synchronous Output Setup
The synchronous output control register (P6SYO) selects the synchronous output pin of the port 6, in each
bit.
The synchronous output event is selected by the pin control register (FLOAT).
When the external interrupt 2 (IRQ2) is selected, the interrupt edge should be specified. The interrupt
edge can be specified by the external interrupt 2 control register (IRQ2ICR) or the both edges interrupt
control register (EDGDT). The synchronous output recognizes the generation of the specified edge as
an event.
Synchronous Output Operation
When the synchronous output control register (P6SYO) is set to disable the synchronous output (I/O port),
the port 6 is functioned as a general port. When the port 6 is set to disable the synchronous output, the
same value to the port 6 output register (P6OUT) is always loaded to the synchronous output value stored
register. (Figure 4-11-1. Block Diagram)
After the output mode is selected by the port 6 direction control register (P6DIR), if the synchronous output
is enabled by the synchronous output control register (P6SYO), the value of the synchronous output value
stored register is output from pins. If the synchronous output event that is set by the pin control register
(FLOAT) is never generated, the synchronous output value stored register holds the same value when the
synchronous output event is enabled.
Store the value that should be output from pin after the synchronous output event is generated, to the
port 6 output register (P6OUT). Once the synchronous output event that is set by the pin control register
(FLOAT) is generated, the data of the synchronous output value stored register is switched to the data of
the port 6 output register (P6OUT), and the output value from pin is changed.
Before the synchronous output is enabled by the synchronous output control register
(P6SYO), set the initial value of the synchronous output to the port 7 output register (P6OUT),
in advance.
IV - 50
Synchronous Output (Port 7)
Table 4-11-2 Synchronous Output Event
Synchronous output port
Output event
Port 6
External interrupt 2
(IRQ2)
Timer 1
Timer 5
Timer7
Page
IV - 26
III - 19, 49
VI - 33
VI - 33
VI - 33
VII - 31