PIC12C5XX
FIGURE 5-2: SUCCESSIVE I/O OPERATION
Q4
Q4
Q4
Q4
Q3
Q3
Q3
Q3
Q1 Q2
PC
MOVWF GPIO
Q1 Q2
Q1 Q2
Q1 Q2
PC + 3
NOP
PC + 1
PC + 2
NOP
This example shows a write to GPIO followed
by a read from GPIO.
Instruction
fetched
MOVF GPIO,W
Data setup time = (0.25 TCY – TPD)
where: TCY = instruction cycle.
TPD = propagation delay
GP5:GP0
Port pin
written here
Port pin
sampled here
Therefore, at higher clock frequencies, a
write followed by a read may be problematic.
Instruction
executed
MOVWF GPIO
(Write to
MOVF GPIO,W
(Read
NOP
GPIO)
GPIO)
1999 Microchip Technology Inc.
DS40139E-page 23