Freescale Semiconductor MPC8260 - Manual (Page 831)

Serial Management Controllers (SMCs)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 27-19
Figure 27-10. SMC UART Interrupts Example
27.3.12 SMC UART Controller Programming Example
The following initialization sequence assumes 9,600 baud, 8 data bits, no parity, and 1 stop bit in a 66-MHz
system. BRG1 and SMC1 are used. (The SMC transparent programming example uses an external clock
configuration; see
Section 27.4.11, “SMC Transparent NMSI Programming Example.” )
1. Configure the port D pins to enable SMTXD1 and SMRXD1. Set PPARD[8,9] and PDIRD[9].
Clear PDIRD[8] and PSORD[8,9].
2. Configure the BRG1. Write BRGC1 with 0x0001_035A. The DIV16 bit is not used and the divider
is 429 (decimal). The resulting BRG1 clock is 16
× the preferred bit rate.
3. Connect BRG1 to SMC1 using the CPM mux by clearing CMXSMR[SMC1, SMC1CS].
4. In address 0x87FC, assign a pointer to the SMC1 parameter RAM.
5. Assuming one RxBD at the beginning of dual-port RAM followed by one TxBD, write RBASE
with 0x0000 and TBASE with 0x0008.
6. Write 0x1D01_0000 to CPCR to execute the INIT RX AND TX PARAMETERS command.
7. Write RFCR and TFCR with 0x10 for normal operation.
8. Write MRBLR with the maximum number of bytes per receive buffer. Assume 16 bytes, so
MRBLR = 0x0010.
9. Write MAX_IDL with 0x0000 in the SMC UART-specific parameter RAM to disable the
MAX_IDL functionality for this example.
10. Clear BRKLN and BRKEC in the SMC UART-specific parameter RAM.
11. Set BRKCR to 0x0001; if a STOP TRANSMIT COMMAND is issued, one break character is sent.
RX RX BRK BRKE
Break
Line Idle
10 Characters
RXD
Characters
Received by SMC UART
Time
Line Idle
TXD
Characters
Transmitted by SMC UART
TX
Line Idle Line Idle
7 Characters
NOTES:
SMC UART SMCE
Events
1. The first RX event assumes receive buffers are 6 bytes each.
2. The second RX event position is programmable based on the MAX_IDL value.
3. The BRK event occurs after the first break character is received.
SMC UART SMCE
Events
NOTES:
The TX event assumes all seven characters were put into a single buffer, and the TX event occurred when the seventh
character was written to the SMC transmit FIFO. 1.