Serial Communication Controllers (SCCs)
MC68360 USER’S MANUAL
Bit 5—Reserved
PEN—Parity Enable
0 = No Parity
1 = Parity is enabled and determined by the parity mode bits.
RPM—Receiver Parity Mode
The RPM bits select the type of parity check to be performed by the receiver. The RPM
bits can be modified on the fly.
00 = Odd Parity
01 = Low Parity (always check for a zero in the parity bit position)
10 = Even Parity
11 = High Parity (always check for a one in the parity bit position)
When odd parity is selected, the transmitter will count the number of ones in the data
word. If the total number of ones is not an odd number, the parity bit is set to one and thus
produces an odd number. If the receiver counts an even number of ones, an error in trans-
mission has occurred. In the same manner, for even parity, an even number must result
from the calculation performed at both ends of the line. In high/low parity (sometimes
called mark/space parity), if the parity bit is not high/low, a parity error is reported.
NOTE
The receive parity errors cannot be disabled, but can be ignored
if desired.
TPM—Transmitter Parity Mode
The TPM bits select the type of parity to be performed for the transmitter. The TPM bits
can be modified on the fly.
00 = Odd Parity
01 = Force Low Parity (always send a zero in the parity bit position)
10 = Even Parity
11 = Force High Parity (always send a one in the parity bit position)
7.10.16.16 UART RECEIVE BUFFER DESCRIPTOR (RX BD). The CP reports informa-
tion concerning the received data on a per-buffer basis via Rx BDs.
The CP closes the current buffer, generates a maskable interrupt, and starts to receive data
into the next buffer after one of the following events:
1. Receiving a user-defined control character (when the reject bit = 0 in the control char-
acter table entry)
2. Detecting an error during message processing
3. Detecting a full receive buffer
4. Receiving a MAX_IDL number of consecutive idle characters
5. Issuing the ENTER HUNT MODE command
6. Issuing the CLOSE Rx BD command
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Freescale Semiconductor, Inc.
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