Freescale Semiconductor PowerQUICC MPC885 Reference Manual page 694

SCC UART Mode
22.20 SCC UART Status Register (SCCS)
The SCC UART status register (SCCS), shown in
real-time status of CTS and CD is part of the port C parallel I/O.
0
Field
Reset
R/W
Addr
Figure 22-12. SCC Status Register for UART Mode (SCCS)
Table 22-13 describes UART SCCS fields.
Bits Name
0–6 — Reserved, should be cleared.
7 ID Idle status. Set when RXD has been a logic one for at least a full character time.
0 The line is not idle
1 The line is idle
22.21 SCC UART Programming Example
The following initialization sequence is for the 9,600 baud, 8 data bits, no parity, and stop bit of an SCC
in UART mode assuming a 25-MHz system frequency. BRG1 and SCC2 are used. The controller is
configured with RTS2, CTS2, and CD2 active; CTS2 acts as an automatic flow-control signal.
1. Configure port A to enable TXD2 and RXD2. Set PAPAR[12,13] and clear PADIR[12,13] and
PAODR[12,13].
2. Configure port C to enable RTS2, CTS2, and CD2. Set PCPAR[14] and PCSO[8,9] and clear
PCPAR[8,9] and PCDIR[8,9,14].
3. Configure BRG1. Write BRGC1 with 0x010144. The DIV16 bit is not used and the divider is 162
(decimal). The resulting BRG1 clock is 16× the preferred bit rate.
4. Connect BRG1 to SCC2 using the serial interface. Clear SICR[R2CS,T2CS].
5. Initialize the SDMA configuration register (SDCR = 0x0001 for normal operation).
6. Connect the SCC2 to the NMSI. Clear SICR[SC2].
7. Write RBASE and TBASE in the SCC2 parameter RAM to point to the RxBD and TxBD tables in
dual-port RAM. Assuming one RxBD at the start of dual-port RAM followed by one TxBD, write
RBASE with 0x0000 and TBASE with 0x0008.
8. Write 0x0041 to CPCR to execute the
updates RBPTR and TBPTR of the serial channel with the new values of RBASE and TBASE.
9. Write RFCR with 0x10 and TFCR with 0x10 for normal operation.
22-22
Figure
—
0000_0000_0000_0000
0xA37 (SCCS2), 0xA57 (SCCS3), 0xA77 (SCCS4)
Table 22-13. UART SCCS Field Descriptions
INIT RX AND TX PARAMS
MPC885 PowerQUICC Family Reference Manual, Rev. 2
22-12, monitors the real-time status of RXD. The
R
Description
command for SCC2. This command
6 7
ID
Freescale Semiconductor