PIC18F24J11 MICROCHIP [Microchip Technology], PIC18F24J11 Datasheet - Page 273

• Manufacturer Part Number: PIC18F24J11
• Description: 28/44-Pin, Low-Power, High-Performance USB Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

19.3.1
Each MSSP module has four registers for SPI mode
operation. These are:
• MSSPx Control Register 1 (SSPxCON1)
• MSSPx Status Register (SSPxSTAT)
• Serial Receive/Transmit Buffer Register
• MSSPx Shift Register (SSPxSR) – Not directly
SSPxCON1 and SSPxSTAT are the control and status
registers in SPI mode operation. The SSPxCON1
register is readable and writable. The lower six bits of
the SSPxSTAT are read-only. The upper two bits of the
SSPxSTAT are read/write.
SSPxSR is the shift register used for shifting data in or
out. SSPxBUF is the buffer register to which data
bytes are written to or read from.
REGISTER 19-1:
 2011 Microchip Technology Inc.
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Note 1:
(SSPxBUF)
accessible
R/W-0
SMP
Polarity of clock state is set by the CKP bit (SSPxCON1<4>).
REGISTERS
SMP: Sample bit
SPI Master mode:
1 = Input data sampled at end of data output time
0 = Input data sampled at middle of data output time
SPI Slave mode:
SMP must be cleared when SPI is used in Slave mode.
CKE: SPI Clock Select bit
1 = Transmit occurs on transition from active to Idle clock state
0 = Transmit occurs on transition from Idle to active clock state
D/A: Data/Address bit
Used in I
P: Stop bit
Used in I
S: Start bit
Used in I
R/W: Read/Write Information bit
Used in I
UA: Update Address bit
Used in I
BF: Buffer Full Status bit
1 = Receive complete, SSPxBUF is full
0 = Receive not complete, SSPxBUF is empty
CKE
R/W-0
SSPxSTAT: MSSPx STATUS REGISTER – SPI MODE (ACCESS FC7h/F73h)
(1)
2
2
2
2
2
C™ mode only.
C mode only; this bit is cleared when the MSSP module is disabled, SSPEN is cleared.
C mode only.
C mode only.
C mode only.
W = Writable bit
‘1’ = Bit is set
D/A
R-0
(1)
R-0
P
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
PIC18F46J11 FAMILY
In receive operations, SSPxSR and SSPxBUF
together create a double-buffered receiver. When
SSPxSR receives a complete byte, it is transferred to
SSPxBUF and the SSPxIF interrupt is set.
During
double-buffered. A write to SSPxBUF will write to both
SSPxBUF and SSPxSR.
R-0
S
Note:
transmission,
Because the SSPxBUF register is dou-
ble-buffered,
instructions such as BCF, COMF, etc., will
not work.
Similarly, when debugging under an in-cir-
cuit debugger, performing actions that
cause
hovering, watch, etc.) can consume data
that the application code was expecting to
receive.
R/W
R-0
reads
x = Bit is unknown
the
using
of
R-0
UA
SSPxBUF
SSPxBUF
DS39932D-page 273
read-modify-write
R-0
BF
(mouse
is
bit 0
not