Serial Management Controllers (SMCs)
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MC68360 USER’S MANUAL
W—Wrap (Final BD in Table)
0 = This is not the last BD in the Rx BD table.
1 = This is the last BD in the Rx BD table. After this buffer has been used, the CP will
receive incoming data into the first BD in the table (the BD pointed to by RBASE).
The number of Rx BDs in this table is programmable and is determined only by the
W-bit and the overall space constraints of the dual-port RAM.
I—Interrupt
0 = No interrupt is generated after this buffer has been filled.
1 = The RX bit in the event register will be set when this buffer has been completely
filled by the CP, indicating the need for the CPU32+ core to process the buffer. The
RX bit can cause an interrupt if it is enabled.
CM—Continuous Mode
0 = Normal operation.
1 = The E-bit is not cleared by the CP after this BD is closed, allowing the associated
data buffer to be overwritten automatically when the CP next accesses this BD.
However, the E-bit will be cleared if an error occurs during reception, regardless of
the CM bit.
The following status bits are written by the CP after the received data has been into the asso-
ciated data buffer.
ID—Buffer Closed on Reception of Idles
The buffer was closed due to the reception of the programmable number of consecutive
idle sequences.
BR—Buffer Closed on Reception of Break
The buffer was closed due to the reception of a break sequence.
FR—Framing Error
A character with a framing error was received and is located in the last byte of this buffer.
A framing error is a character without a stop bit. A new receive buffer will be used for fur-
ther data reception.
PR—Parity Error
A character with a parity error was received and is located in the last byte of this buffer. A
new receive buffer will be used for further data reception.
OV—Overrun
A receiver overrun occurred during message reception.
Data Length
Data length is the number of octets that the CP has written into this BD’s data buffer. It is
written only once by the CP as the BD is closed.
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Freescale Semiconductor, Inc.
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