MC68000 MOTOROLA [Motorola, Inc], MC68000 Datasheet - Page 448

• Manufacturer Part Number: MC68000
• Manufacturer: MOTOROLA [Motorola, Inc]

SCC Programming Reference
E.2.1.4.1 Receive BD Control/Status Word. To initialize the buffer, the user should write
bits 15-12 and clear bits 11-0. The IMP clears bit 15 when the buffer is closed and sets bits
5-0 depending on which error occurred.
E—Empty
X—External Buffer
W—Wrap (final BD in table)
I—Interrupt
C—Control Character
A—Address
M—Address Match
ID—IDLE Reception
E-26
OFFSET + 0
OFFSET +2
OFFSET +4
OFFSET +6
0 = This data buffer is full or has been closed due to an error condition.
1 = This data buffer is empty; must be set by the user to enable reception into this buff-
0 = The data butter associated with this BD is in internal dual-port RAM.
1 = The data buffer associated with this BD is in external memory.
0 = This is not the last BD in the receive BD table.
1 = This is the last BD in the receive BD table.
0 = The RX bit in the event register is not set when this buffer is closed.
1 = The RX bit in the event register is set when this buffer is closed.
0 = This buffer does not contain a control character.
1 = The last byte of this buffer contains a control character.
0 = This buffer contains data only.
1 = The first byte of this data buffer is an address byte.
0 = The address byte matched UADDR2.
1 = The address byte matched UADDR1.
0 = Buffer not closed due to reception of maximum number of IDLE characters
1 = Buffer closed due to reception of maximum number of IDLE characters (MAX_IDL).
er.
(MAX_IDL).
15
E
14
X
13
W
12
I
11
C
MC68360 USER’S MANUAL
10
A
M
9
RX BUFFER POINTER
DATA LENGTH
ID
8
—
7
—
6
BR
5
FR
4
PR
3
—
2
MOTOROLA
OV
1
CD
0