AN1212 Freescale Semiconductor / Motorola, AN1212 Datasheet - Page 22

• Manufacturer Part Number: AN1212
• Description: J1850 Multiplex Bus Communication Using the MC68HC705C8 and the SC371016 J1850 Communications Interface (JCI)
• Manufacturer: Freescale Semiconductor / Motorola

AN1212/D
22
NO
NO
byte" BIT COMBINATION
INTO SPDR, INITIATING
LOCATION "data" INTO
LOCATION "command"
LOCATION "command"
LOAD BYTE IN SPDR
LOAD BYTE IN RAM
LOAD BYTE IN RAM
LOAD "load as data
LOAD FIRST BYTE
LOCATION "status"
SPDR, INITIATING
LOCATION "data"
OF FRAME INTO
INTO MCU RAM
INTO MCU RAM
SPI TRANSFER
SPI TRANSFER
SPI TRANSFER
SPI TRANSFER
CALL TXDATA
SUBROUTINE
COMPLETE?
COMPLETE?
YES
YES
MCU RAM
IS
IS
J1850 Multiplex Bus Communication Using the MC68HC705C8
and the SC371016 J1850 Communications Interface (JCI)
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 12. TXDATA Subroutine
Go to: www.freescale.com
NO
NO
INTO SPDR, INITIATING
LOCATION "data": INTO
LOCATION "command"
LOAD BYTE IN SPDR
LOAD NEXT FRAME
LOAD BYTE IN RAM
LOAD BYTE IN RAM
LOCATION "status"
SPDR, INITIATING
BYTE INTO MCU
THE LAST BYTE
RAM LOCATION
INTO MCU RAM
SPI TRANSFER
SPI TRANSFER
SPI TRANSFER
SPI TRANSFER
COMPLETE?
COMPLETE?
OF FRAME?
YES
YES
NO
IS THIS
"data"
IS
IS
YES
NO
NO
byte" BIT COMBINATION
INTO SPDR, INITIATING
LOCATION "data" INTO
LOCATION "command"
LOCATION "command"
LOAD BYTE IN SPDR
LOAD BYTE IN RAM
LOAD BYTE IN RAM
LOCATION "status"
SPDR, INITIATING
LOAD "load as last
RETURN FROM
INTO MCU RAM
SPI TRANSFER
SPI TRANSFER
INTO MCU RAM
SPI TRANSFER
SPI TRANSFER
SUBROUTINE
COMPLETE?
COMPLETE?
YES
YES
IS
IS
MOTOROLA