MC68HC812A4 Datasheet, PDF (282/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Serial Peripheral Interface (SPI)
15.12 Synchronous Character Transmission using the SPI
This program is intended to communicate with the HC11 on the UDLP1
board. It utilizes the SPI to transmit synchronously characters in a string
to be displayed on the LCD display. The program must configure the SPI
as a master, and non-interrupt driven. The slave peripheral is
chip-selected with the SS line at low voltage level. Between 8 bit
transfers the SS line is held high. Also the clock idles low and takes data
on the rising clock edges. The serial clock is set not to exceed 100 kHz
baud rate.
15.12.1 Equipment
For this exercise, use the M68HC812A4EVB emulation board.
15.12.2 Code Listing
NOTE:
A comment line is deliminted by a semi-colon. If there is no code before
comment, an “;” must be placed in the first column to avoid assembly
errors.
INCLUDE 'EQUATES.ASM'
;Equates for all registers
; User Variables
; Bit Equates
; ----------------------------------------------------------------------
;
MAIN PROGRAM
; ----------------------------------------------------------------------
ORG $7000
; 16K On-Board RAM, User code data area,
;
; start main program at $7000
MAIN:
BSR INIT
; Subroutine to initialize SPI registers
BSR TRANSMIT
; Subroutine to start transmission
FINISH:
BRA FINIS
; Finished transmitting all DATA
MC68HC812A4 — Rev. 3.0
282
Serial Peripheral Interface (SPI)
Advance Information
MOTOROLA