SCC BISYNC Mode
MPC885 PowerQUICC Family Reference Manual, Rev. 2
Freescale Semiconductor
26-17
After ETX, a BCS is expected, then the buffer should be closed. Hunt mode should be entered when a line
turnaround occurs. ENQ characters are used to stop sending a block and to designate the end of the block
for a receiver, but no CRC is expected. After control character reception, set SCCM[RCH] to re-enable
interrupts for each byte of data received.
26.17 SCC BISYNC Programming Example
This BISYNC controller initialization example for SCC2 uses an external clock. The controller is
configured with RTS2, CTS2, and CD2 active. Both the receiver and transmitter use CLK3.
1. Configure the port A pins to enable TXD2 and RXD2. Write PAPAR[12,13] and PAODR[12,13]
with ones and PADIR[12,13] with zeros.
2. Configure the port C pins to enable RTS2, CTS2, and CD2. Set PCSO[8,9] and PCPAR[14]; clear
PCPAR[8,9] and PCDIR[8,9,14].
3. Configure port A to enable CLK3. Set PAPAR[5] and clear PADIR[5].
4. Connect CLK3 to SCC2 using the serial interface. Set SICR[R2CS, T2CS] to 0b110.
5. Connect the SCC2 to the NMSI and clear SICR[SC2].
6. Initialize the SDMA configuration register (SDCR).
7. Assuming one RxBD at the beginning of dual-port RAM followed by one TxBD, write RBASE
with 0x0000 and TBASE with 0x0008.
8. Write 0x0041 to CPCR to execute the
INIT
RX
AND
TX
PARAMS
command for SCC2. This command
updates RBPTR and TBPTR of the serial channel with the new values of RBASE and TBASE.
9. Write RFCR and TFCR with 0x10 for normal operation.
10. Write MRBLR with the maximum number of bytes per receive buffer. For this case, assume 16
bytes, so MRBLR = 0x0010.
11. Write PRCRC with 0x0000 to comply with CRC16.
12. Write PTCRC with 0x0000 to comply with CRC16.
13. Clear PAREC for clarity.
14. Write BSYNC with 0x8033, assuming a SYNC value of 0x33.
15. Write DSR with 0x3333.
16. Write BDLE with 0x8055, assuming a DLE value of 0x55.
17. Write CHARACTER1–8 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].
21. Write 0xFFFF to SCCE to clear any previous events.
22. Write 0x0013 to SCCM to enable the TXE, TXB, and RXB interrupts.
Summary of Contents for PowerQUICC MPC870
Page 98: ...MPC885 PowerQUICC Family Reference Manual Rev 2 I 4 Freescale Semiconductor ...
Page 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Page 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Page 288: ...MPC885 PowerQUICC Family Reference Manual Rev 2 III 4 Freescale Semiconductor ...
Page 554: ...MPC885 PowerQUICC Family Reference Manual Rev 2 V 6 Freescale Semiconductor ...
Page 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Page 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
Page 1336: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 16 Freescale Semiconductor ...
Page 1358: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 38 Freescale Semiconductor ...
Page 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Page 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...