Serial Communication Controllers (SCCs)
7-212
MC68360 USER’S MANUAL
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
2. Detecting an error
3. Detecting a full receive buffer
4. Issuing the ENTER HUNT MODE command
5. Issuing the CLOSE Rx BD command
NOTE: Entries in boldface must be initialized by the user.
E—Empty
0 = The data buffer associated with this Rx BD has been filled with received data, or
data reception has been aborted due to an error condition. The CPU32+ core is
free to examine or write to any fields of this Rx BD. The CP will not use this BD
again while the E-bit remains zero.
1 = The data buffer associated with this Rx BD is empty, or reception is currently in
progress. This Rx BD and its associated receive buffer are owned by the CP. Once
the E-bit is set, the CPU32+ core should not write any fields of this Rx BD.
Bits 14, 8, 6, 5—Reserved
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 used.
1 = The RX bit in the BISYNC event register will be set when this buffer has been
closed by the BISYNC controller. The RX bit can cause an interrupt if it is enabled.
L—Last in Frame
This bit is set by the transparent controller when this buffer is the last in a frame. This
implies the negation of CD in envelope mode or the reception of an error, in which
212
15
14
13
12
11
10
9876543210
OFFSET + 0
E
—
W
IL
F
CM
—DE—
—
NO
—
CR
OV
CD
OFFSET + 2
DATA LENGTH
OFFSET + 4
RX DATA BUFFER POINTER
OFFSET + 6
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
..
.