PIC18F25K20T-ISS Datasheet, PDF (258/456 Pages) Microchip Technology – 28/40/44-Pin Flash Microcontrollers with nanoWatt XLP Technology

PIC18F2XK20/4XK20
18.4.1.5 Synchronous Master Transmission
Set-up:
1. Initialize the SPBRGH, SPBRG register pair and
the BRGH and BRG16 bits to achieve the
desired baud rate (see Section 18.3 “EUSART
Baud Rate Generator (BRG)”).
2. Set the RX/DT and TX/CK TRIS controls to ‘1’.
3. Enable the synchronous master serial port by
setting bits SYNC, SPEN and CSRC. Set the
TRIS bits corresponding to the RX/DT and
TX/CK I/O pins.
4. Disable Receive mode by clearing bits SREN
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 TXIE, GIE and
PEIE interrupt enable bits.
8. If 9-bit transmission is selected, the ninth bit
should be loaded in the TX9D bit.
9. Start transmission by loading data to the
TXREG register.
FIGURE 18-10: SYNCHRONOUS TRANSMISSION
RX/DT
pin
bit 0
bit 1
bit 2
bit 7
bit 0
bit 1
bit 7
Word 1
Word 2
TX/CK pin
(SCKP = 0)
TX/CK pin
(SCKP = 1)
Write to
TXREG Reg
TXIF bit
(Interrupt Flag)
Write Word 1
TRMT bit
Write Word 2
TXEN bit ^{‘1’}
‘1’
Note:
Sync Master mode, SPBRG = 0, continuous transmission of two 8-bit words.
FIGURE 18-11: SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
RX/DT pin
bit 0
bit 1
bit 2
bit 6
bit 7
TX/CK pin
Write to
TXREG reg
TXIF bit
TRMT bit
TXEN bit
DS41303G-page 258
 2010 Microchip Technology Inc.