Datasheet

 2003-2013 Microchip Technology Inc. DS39609C-page 129

PIC18F6520/8520/6620/8620/6720/8720

FIGURE 10-24: PARALLEL SLAVE PORT WRITE WAVEFORMS

R-0 R-0 R/W-0 R/W-0 U-0 U-0 U-0 U-0

IBF OBF IBOV PSPMODE — — — —

bit 7 bit 0

bit 7 IBF: Input Buffer Full Status bit

1 = A word has been received and is waiting to be read by the CPU

0 = No word has been received

bit 6 OBF: Output Buffer Full Status bit

1 = The output buffer still holds a previously written word

0 = The output buffer has been read

bit 5 IBOV: Input Buffer Overflow Detect bit

1 = A write occurred when a previously input word has not been read

(must be cleared in software)

0 = No overflow occurred

bit 4 PSPMODE: Parallel Slave Port Mode Select bit

1 = Parallel Slave Port mode

0 = General Purpose I/O mode

bit 3-0 Unimplemented: Read as ‘0’

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

Q1 Q2 Q3 Q4

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

IBF

OBF

PSPIF

PORTD<7:0>