Motorola MPC8260 - Manual (Page 666)

23-14 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA
Part IV. Communications Processor Module
1. ConÞgure port D pins to enable TXD2 and RXD2. Set PPARD[27,28] and
PDIRD[27] and clear PDIRD[28] and PSORD[27,28].
2. ConÞgure ports C and D pins to enable RTS2, CTS2 and CD2. Set PPARD[26],
PPARC[12,13] and PDIRD[26] and clear PDIRC[12,13], PSORC[12,13] and
PSORD[26].
3. ConÞgure port C pin 29 to enable the CLK3 pin. Set PPARC[29] and clear
PDIRC[29] and PSORC[29].
4. Connect CLK3 to SCC2 using the CPM mux. Program CMXSCR[R2CS] and
CMXSCR[T2CS] to 0b110.
5. Connect the SCC2 to the NMSI and clear CMXSCR[SC2].
6. Write RBASE with 0x0000 and TBASE with 0x0008 in the SCC2 parameter RAM
to point to one RxBD at the beginning of dual-port RAM followed by one TxBD.
7. Write 0x04A1_0000 to the CPCR to execute INIT RX AND TX PARAMETERS for
SCC2.
8. Write 0x0041 to the CPCR to execute INIT RX AND TX PARAMETERS for SCC2.
9. Write RFCR and TFCR with 0x10 for normal operation.
10. Write MRBLR with the maximum number of bytes per receive buffer and assume
16-bytes, so MRBLR = 0x0010.
11. Write CRC_P with 0x0000_FFFF to comply with the 16-bit CRC-CCITT.
12. Write CRC_C with 0x0000_F0B8 to comply with the 16-bit CRC-CCITT.
13. Initialize the RxBD. Assume the Rx buffer is at 0x0000_1000 in main memory.
Write 0xB000 to RxBD[Status and Control], 0x0000 to RxBD[Data Length]
(optional), and 0x0000_1000 to RxBD[Buffer Pointer].
14. Initialize the TxBD. Assume the Tx buffer is at 0x0000_2000 in main memory and
contains Þve 8-bit characters. Write 0xBC00 to TxBD[Status and Control], 0x0005
to TxBD[Data Length], and 0x0000_2000 to TxBD[Buffer Pointer].
15. Write 0xFFFF to SCCE to clear any previous events.
16. Write 0x0013 to SCCM to enable the TXE, TXB, and RXB interrupts.
17. Write 0x0040_0000 to the SIU interrupt mask register low (SIMR_L) so SMC1 can
generate a system interrupt. Initialize SIU interrupt pending register low (SIPNR_L)
by writing 0xFFFF_FFFF to it.
18. Write 0x0000_1980 to GSMR_H2 to conÞgure the transparent channel.
19. Write 0x0000_0000 to GSMR_L2 to conÞgure CTS and CD to automatically
control transmission and reception (DIAG bits). Normal operation of the transmit
clock is used. Note that the transmitter (ENT) and receiver (ENR) are not enabled
yet.
20. Write 0x0000_0030 to GSMR_L2 to enable the SCC2 transmitter and receiver. This
additional write ensures that the ENT and ENR bits are enabled last.