PIC18F24 MICROCHIP [Microchip Technology], PIC18F24 Datasheet - Page 154

• Manufacturer Part Number: PIC18F24
• Description: 28/40-Pin High-Performance, Enhanced Flash Microcontrollers with CAN Module
• Manufacturer: MICROCHIP [Microchip Technology]

17.4
The MSSP module in I
master and slave functions (including general call
support) and provides interrupts on Start and Stop bits
in hardware to determine a free bus (multi-master
function). The MSSP module implements the standard
mode specifications, as well as 7-bit and 10-bit
addressing.
Two pins are used for data transfer:
• Serial clock (SCL) – RC3/SCK/SCL
• Serial data (SDA) – RC4/SDI/SDA
The user must configure these pins as inputs or outputs
through the TRISC<4:3> bits.
FIGURE 17-7:
DS41159D-page 152
PIC18FXX8
RC3/SCK/
RC4/
SDI/
SDA
SCL
I
2
C Mode
Read
Shift
Clock
MSb
MSSP BLOCK DIAGRAM
(I
2
2
Stop bit Detect
Match Detect
SSPADD reg
SSPBUF reg
C mode fully implements all
C™ MODE)
SSPSR reg
Start and
LSb
Write
(SSPSTAT reg)
Internal
Data Bus
Set, Reset
S, P bits
Addr Match
17.4.1
The MSSP module has six registers for I
These are:
• MSSP Control Register 1 (SSPCON1)
• MSSP Control Register 2 (SSPCON2)
• MSSP Status Register (SSPSTAT)
• Serial Receive/Transmit Buffer (SSPBUF)
• MSSP Shift Register (SSPSR) – Not directly
• MSSP Address Register (SSPADD)
SSPCON1, SSPCON2 and SSPSTAT are the control
and status registers in I
SSPCON1 and SSPCON2 registers are readable and
writable. The lower 6 bits of the SSPSTAT are read-only.
The upper two bits of the SSPSTAT are read/write.
SSPSR is the shift register used for shifting data in or
out. SSPBUF is the buffer register to which data bytes
are written to or read from.
SSPADD register holds the slave device address
when the SSP is configured in I
the SSP is configured in Master mode, the lower
seven bits of SSPADD act as the Baud Rate
Generator reload value.
In receive operations, SSPSR and SSPBUF together
create a double-buffered receiver. When SSPSR
receives a complete byte, it is transferred to SSPBUF
and the SSPIF interrupt is set.
During transmission, the SSPBUF is not double-
buffered. A write to SSPBUF will write to both SSPBUF
and SSPSR.
accessible
REGISTERS
 2004 Microchip Technology Inc.
2
C mode operation. The
2
C Slave mode. When
2
C operation.