SCC UART Mode
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 21-11
21.15 Handling Errors in the SCC UART Controller

The UART controller reports character reception and transmission error conditions via the BDs, the error

counters, and the SCCE. Modem interface lines can be monitored by the port C pins. Transmission errors

are described in Table 21-7.

Reception errors are described in Table21-8.

Table21-6. DSR Fields Descriptions

Bit Name Description
0 — 0b0
1–4 FSB Fractional stop bits. For 16× oversampling:
1111 Last transmitted stop bit 16/16. Default value after reset.
1110 Last transmitted stop bit 15/16.
1000 Last transmitted stop bit 9/16.
0xxx Invalid. Do not use.
For 32× oversampling:
1111 Last transmitted stop bit 32/32. Default value after reset.
1110 Last transmitted stop bit 31/32.
0000 Last transmitted stop bit 17/32.
For 8× oversampling:
1111 Last transmitted stop bit 8/8. Default value after reset.
1110 Last transmitted stop bit 7/8.
1101 Last transmitted stop bit 6/8.
1100 Last transmitted stop bit 5/8.
10xx Invalid. Do not use.
0xxx Invalid. Do not use.
The UART receiver can always receive fractional stop bits. The next character’s start bit can begin
any time after the three middle samples have been taken.
5–6 — 0b11
7–8 — 0b00
9–14 — 0b111111
15 — 0b0

Table21-7. Transmission Errors

Error Description
CTS Lost
during
Character
Transmission
When CTS negates during transmission, the channel stops after finishing the current character. The
CP sets TxBD[CT] and generates the TX interrupt if it is not masked. The channel resumes
transmission after the RESTART TRANSMIT command is issued and CTS is asserted.
Note that if CTS is used, the UART also offers an asynchronous flow control option that does not
generate an error. See the description of PSMR[FLC] in Table21-9.