
SCC Programming Reference
MOTOROLA
MC68360 USER’S MANUAL
E-9
RXB—Rx Buffer
0 = No interrupt
1 = A buffer that was not a complete frame was received on the HDLC channel (set
only if the I bit in the Rx buffer descriptor is set).
E.1.1.2.5 HDLC Mask Register (SCCM).
(SCC1), $89A (SCC2), and $8AA (SCC3) on D15-D8 of a 16-bit data bus. The SCCM is
used to enable and disable interrupt events reported by the SCCE. The mask bits corre-
spond to the interrupt event bit shown in the SCCE. A bit should be set to one to enable the
corresponding interrupt in the SCCE.
This 8-bit register is located at offset $88A
E.1.1.2.6 HDLC Status Register (SCCS).
(SCC1), $89C (SCC2), and $8AC (SCC3) on D15-D8 of a 16-bit data bus. The SCCS reg-
ister reflects the current status of the RXD, CD, and CTS lines as seen by the SCC.
This 8-bit register is located at offset $88C
ID—Idle Status on the Receiver Line (valid only when the ENR bit is set and the receive
clock is running)
0 = Receiver line is not idling.
1 = Either CD is not asserted or the receiver line is idling while CD is asserted.
CD—Carrier Detect Status Changed (valid only when the ENR bit is set and the receive
clock is running)
0 = CD is asserted.
1 = CD is not asserted.
CTS—Clear-To-Send Status Changed (valid only when the ENT bit is set and the transmit
clock is running)
0 = CTS is asserted.
1 = CTS is not asserted.
E.1.1.3 GENERAL AND HDLC PROTOCOL-SPECIFIC PARAMETER RAM.
has 32 words of parameter RAM used to configure receive and transmit operation, store
temporary parameters for the CP, and maintain counters. The first 14 words are general
parameters, which are the same for each protocol. The last 18 words are specific to the pro-
tocol selected. The following sections discuss the parameters that the user must initialize to
configure the HDLC operation.
Each SCC
E.1.1.3.1 RFCR/TFCR—Rx Function Code/Tx Function Code.
contains the function codes of the receive data buffers and transmit data buffers. The user
must initialize the function codes (FC2-FC0) to a value less than 7.
This 16-bit parameter
7
6
5
4
3
2
1
0
CTS
CD
IDL
TXE
RXF
BSY
TXB
RXB
7
—
6
—
5
—
4
—
3
—
2
ID
1
0
CD
CTS