MC68000 MOTOROLA [Motorola, Inc], MC68000 Datasheet - Page 450

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

SCC Programming Reference
X—External Buffer
W—Wrap (final BD in table)
I—Interrupt
CR—Clear-to-Send Report
A—Address
P—Preamble
Bits 8–1—Reserved for future use
CT—CTS Lost
E.2.1.5.2 Transmit Buffer Data Length. This 16-bit value is written by the user to indicate
the number of octets to be transmitted from the data butter.
E2.1.5.3 Transmit Buffer Pointer. This 32-bit value is written by the user to indicate the
address of the first byte of data in the data buffer.
E.2.2 Programming the SCC for UART
This section gives a generic algorithm for programming an SCC to handle UART. The algo-
rithm is intended to show what must be done and in what order to initialize the SCC and pre-
pare the SCC for transmission and reception. The algorithm is not specific and assumes that
the lMP and other on-chip peripherals have been initialized as required by the system hard-
ware (timers, chip selects, etc.).
E-28
0 = The data buffer 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 transmit BD table.
1 = This is the last BD in the transmit BD table.
0 = The TXB bit in the event register is not set when this buffer is closed.
1 = The TXB bit in the event register is set if this buffer closed without an error. If an
0 = The buffer following this buffer, if ready, will be transmitted with no delay; less pre-
1 = Normal CTS lost (CT bit) error reporting, and two bits of idle occur between back-
0 = This buffer contains data only.
1 = This buffer contains address character(s) only.
0 = No preamble sequence is sent.
1 = The UART sends a preamble sequence (set of 9 to 13 bits) before sending the da-
0 = No CTS or L1GR lost was detected during frame transmission.
1 = CTS in NMSI mode or L1GR in IDL/GCI mode was lost during frame transmission.
error occurred, then TXE is set.
cise CT bit reporting.
to-back buffers.
ta.
MC68360 USER’S MANUAL
MOTOROLA