PIC16F872 Datasheet, PDF (66/160 Pages) Microchip Technology – 28-Pin, 8-Bit CMOS FLASH Microcontroller

PIC16F872
9.2.5 MASTER MODE
Master mode of operation is supported by interrupt
generation on the detection of the START and STOP
conditions. The STOP (P) and START (S) bits are
cleared from a RESET or when the MSSP module is
disabled. Control of the I²C bus may be TACKEN when
the P bit is set, or the bus is idle with both the S and P
bits clear.
In Master mode, the SCL and SDA lines are manipu-
lated by the MSSP hardware.
The following events will cause the SSP Interrupt Flag
bit, SSPIF, to be set (SSP Interrupt if enabled):
• START condition
• STOP condition
• Data transfer byte transmitted/received
• Acknowledge transmit
• Repeated Start
FIGURE 9-9: SSP BLOCK DIAGRAM (I²C MASTER MODE)
SDA
SDA in
Read
Internal
Data Bus
Write
SSPBUF
SSPSR
MSb
Shift
Clock
LSb
SSPM<3:0>,
SSPADD<6:0>
Baud
Rate
Generator
SCL
Start bit, Stop bit,
Acknowledge
Generate
SCL in
Bus Collision
Start bit detect,
Stop bit detect
Write collision detect
Clock Arbitration
State counter for
end of XMIT/RCV
Set/Reset, S, P, WCOL (SSPSTAT)
Set SSPIF, BCLIF
Reset ACKSTAT, PEN (SSPCON2)
DS30221A-page 66
Preliminary
© 1999 Microchip Technology Inc.