MPC8280 datasheet(773/1386 Pages) FREESCALE

773 / 1386 page

SCC BISYNC Mode

MPC8280 PowerQUICC II Family Reference Manual, Rev. 1

Freescale Semiconductor

23-19

17. Write CHARACTER2–8 with 0x8000. They are not used.

18. Write RCCM with 0xE0FF. It is not used.

19. Initialize the RxBD and assume the data buffer is at 0x00001000 in main memory. Then write

0xB000 to RxBD[Status and Control], 0x0000 to RxBD[Data Length] (optional), and 0x00001000

to RxBD[Buffer Pointer].

20. Initialize the TxBD and assume the Tx data buffer is at 0x00002000 in main memory and contains

five 8-bit characters. Then write 0xBD20 to TxBD[Status and Control] 0x0005 to TxBD[Data

Length], and 0x00002000 to TxBD[Buffer Pointer]. Note that ETX character should be written at

the end of user’s data.

21. Write 0xFFFF to SCCE to clear any previous events.

22. Write 0x0013 to SCCM to enable the TXE, TXB, and RXB interrupts.

23. Write 0x0040_0000 to the SIU interrupt mask register low (SIMR_L) so the SMC1 can generate a

system interrupt. Initialize SIU interrupt pending register low (SIPNR_L) by writing

0xFFFF_FFFF to it.

24. Write 0x0000002C to GSMR_H2 to configure a small receive FIFO width.

25. Write 0x00000008 to GSMR_L2 to configure CTS and CD to automatically control transmission

and reception (DIAG bits) and the BISYNC mode. Notice that the transmitter (ENT) and receiver

(ENR) are not yet enabled.

26. Set PSMR to 0x0600 to configure CRC16, CRC checking on receive, and normal operation (not

transparent).

27. Write 0x00000038 to GSMR_L2 to enable the SCC2 transmitter and receiver. This additional write

ensures that ENT and ENR are enabled last.

Write 0x00000038 to GSMR_L2 to enable the SCC2 transmitter and receiver. This additional write

ensures that ENT and ENR are enabled last. After 5 bytes are sent, the TxBD is closed. The buffer is closed

after 16 bytes are received. Any received data beyond 16 bytes causes a busy (out-of-buffers) condition

since only one RxBD is prepared.

MPC8280 Datasheet(PDF) 773 Page - Freescale Semiconductor, Inc