Microchip Technology MA160014 Scheda Tecnica
2010-2012 Microchip Technology Inc.
DS41412F-page 289
PIC18(L)F2X/4XK22
16.5.1.5
Synchronous Master Transmission
Setup:
Setup:
1.
Initialize the SPBRGHx, SPBRGx register pair
and the BRGH and BRG16 bits to achieve the
desired baud rate (see
and the BRGH and BRG16 bits to achieve the
desired baud rate (see
).
2.
Set the RXx/DTx and TXx/CKx TRIS controls to
‘1’.
‘1’.
3.
Enable the synchronous master serial port by
setting bits SYNC, SPEN and CSRC. Set the
TRIS bits corresponding to the RXx/DTx and
TXx/CKx I/O pins.
setting bits SYNC, SPEN and CSRC. Set the
TRIS bits corresponding to the RXx/DTx and
TXx/CKx I/O pins.
4.
Disable Receive mode by clearing bits SREN
and CREN.
and CREN.
5.
Enable Transmit mode by setting the TXEN bit.
6.
If 9-bit transmission is desired, set the TX9 bit.
7.
If interrupts are desired, set the TXxIE, GIE/
GIEH and PEIE/GIEL interrupt enable bits.
GIEH and PEIE/GIEL interrupt enable bits.
8.
If 9-bit transmission is selected, the ninth bit
should be loaded in the TX9D bit.
should be loaded in the TX9D bit.
9.
Start transmission by loading data to the
TXREGx register.
TXREGx register.
FIGURE 16-10:
SYNCHRONOUS TRANSMISSION
FIGURE 16-11:
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
bit 0
bit 1
bit 7
Word 1
bit 2
bit 0
bit 1
bit 7
RXx/DTx
Write to
TXREGx Reg
TXREGx Reg
TXxIF bit
(Interrupt Flag)
(Interrupt Flag)
TXEN bit
‘1’
‘1’
Word 2
TRMT bit
Write Word 1
Write Word 2
Note:
Sync Master mode, SPBRGx = 0, continuous transmission of two 8-bit words.
pin
TXx/CKx pin
TXx/CKx pin
(SCKP = 0)
(SCKP = 1)
RXx/DTx pin
TXx/CKx pin
Write to
TXREGx reg
TXxIF bit
TRMT bit
bit 0
bit 1
bit 2
bit 6
bit 7
TXEN bit