MC68000 MOTOROLA [Motorola, Inc], MC68000 Datasheet - Page 447

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

E—End of Table
R—Reject Character
E.2.1.3.12 Character8—Control Characters8. This 16-bit table entry defines a control
character that should be compared to the incoming characters or is used to transmit out-of
sequence characters, such as XON and XOFF.
E—End of Table
R—Reject Character
REA—Ready
I—Interrupt
CT—Clear-to Send Lost
A—Address
E.2.1.4 RECEIVE BUFFER DESCRIPTORS. Each SCC has eight receive buffer descrip-
tors. Each buffer descriptor consists of four words as shown below. Reserved bits in regis-
ters should be written as zeros.
MOTOROLA
15
E
0 = This entry is valid.
1 = This entry is not valid. No valid entries lie beyond this entry.
0 = The control character is written into the receive data buffer, and the buffer is then
1 = The control character is written to the RCCR instead of the received data butter.
0 = This entry is valid as a receive control character.
1 = This entry contains a character to be transmitted out of sequence.
0 = Must be zero to use this entry as a flow control transmission character, otherwise,
1 = For receive control characters, the meaning is the same as for CHARACTERS 1-7.
0 = Character is not ready for transmission
1 = Character is ready for transmission
0 = No interrupt.
1 = The TX bit in the event register will be set when this character is transmitted.
0 = CTS remained asserted.
1 = CTS was negated during transmission of this character.
0 = Address bit of zero will be transmitted if a multidrop mode is chosen.
1 = Address bit of one will be transmitted if a multidrop mode is chosen.
14
R
closed. A new receive buffer is used if there is more data in the message.
The current buffer is not closed.
function is the same as for CHARACTERS 1-7.
REA
13
12
I
CT
11
10
0
MC68360 USER’S MANUAL
9
0
A
8
7
CHARACTER8
SCC Programming Reference
E-25
0