Datasheet

PIC16(L)F1512/3
DS41624B-page 218 Preliminary  2012 Microchip Technology Inc.
20.6.6.1 BF Status Flag
In Transmit mode, the BF bit of the SSPSTAT register
is set when the CPU writes to SSPBUF and is cleared
when all 8 bits are shifted out.
20.6.6.2 WCOL Status Flag
If the user writes the SSPBUF when a transmit is
already in progress (i.e., SSPSR is still shifting out a
data byte), the WCOL is set and the contents of the
buffer are unchanged (the write does not occur).
WCOL must be cleared by software before the next
transmission.
20.6.6.3 ACKSTAT Status Flag
In Transmit mode, the ACKSTAT bit of the SSPCON2
register is cleared when the slave has sent an
Acknowledge (ACK
= 0) and is set when the slave
does not Acknowledge (ACK
= 1). A slave sends an
Acknowledge when it has recognized its address
(including a general call), or when the slave has
properly received its data.
20.6.6.4 Typical Transmit Sequence:
1. The user generates a Start condition by setting
the SEN bit of the SSPCON2 register.
2. SSPIF is set by hardware on completion of the
Start.
3. SSPIF is cleared by software.
4. The MSSP module will wait the required start
time before any other operation takes place.
5. The user loads the SSPBUF with the slave
address to transmit.
6. Address is shifted out the SDA pin until all eight
bits are transmitted. Transmission begins as
soon as SSPBUF is written to.
7. The MSSP module shifts in the ACK
bit from the
slave device and writes its value into the
ACKSTAT bit of the SSPCON2 register.
8. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the SSPIF
bit.
9. The user loads the SSPBUF with eight bits of
data.
10. Data is shifted out the SDA pin until all eight bits
are transmitted.
11. The MSSP module shifts in the ACK
bit from the
slave device and writes its value into the
ACKSTAT bit of the SSPCON2 register.
12. Steps 8-11 are repeated for all transmitted data
bytes.
13. The user generates a Stop or Restart condition
by setting the PEN or RSEN bits of the
SSPCON2 register. Interrupt is generated once
the Stop/Restart condition is complete.