Datasheet

PIC18F2420/2520/4420/4520
DS39631E-page 192 © 2008 Microchip Technology Inc.
FIGURE 17-21: I
2
C MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESSING)
SDA SCL SSPIF BF (SSPSTAT<0>) SEN
A7 A6 A5 A4 A3 A2 A1 ACK
= ‘0’ D7D6D5D4D3D2D1D0
ACK
Transmitting Data or Second Half
R/W = 0Transmit Address to Slave
123456789 123456789
P
Cleared in software service routine
SSPBUF is written in software
from MSSP interrupt
After Start condition, SEN cleared by hardware
S
SSPBUF written with 7-bit address and R/W
start transmit
SCL held low
while CPU
responds to SSPIF
SEN = 0
of 10-Bit Address
Write SSPCON2<0> SEN = 1 Start condition begins
From slave, clear ACKSTAT bit SSPCON2<6>
ACKSTAT in SSPCON2 = 1
Cleared in software
SSPBUF written
PEN
R/W
Cleared in software