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Serial Communication Controllers (SCCs)
7-120
MC68360 USER’S MANUAL
less of whether serial clocks are present. See 7.10.14 Disabling the SCCs on the Fly for
a description of the proper methods to disable and reenable an SCC.
NOTE
The SCC provides other tools to control reception besides the
ENR bit. They are the ENTER HUNT MODE command, the
CLOSE Rx BD command, and the E-bit in the Rx BD.
ENT—Enable Transmit
This bit enables the transmitter hardware state machine for this SCC. When ENT is
cleared, the transmitter is disabled. If ENT is cleared during transmission, the transmitter
aborts the current character, and the TXD pin returns to the idle state. Data already in the
transmit shift register will not be transmitted. ENT may be set or cleared regardless of
whether serial clocks are present. See 7.10.14 Disabling the SCCs on the Fly for a de-
scription of the proper methods to disable and reenable an SCC.
NOTE
The SCC provides other tools to control transmission besides
the ENT bit. They are the STOP TRANSMIT command, the
GRACEFUL STOP TRANSMIT command, the RESTART
TRANSMIT command, the freeze option in UART mode, the
CTS flow control option in UART mode, and the ready (R) bit in
the Tx BD.
MODE—Channel Protocol mode
0000 = HDLC
0001 = Reserved
0010 = AppleTalk (LocalTalk)
0011 = SS7 (reserved for RAM microcode)
0100 = UART
0101 = Profibus (reserved for RAM microcode)
0110 = Async HDLC (reserved for RAM microcode)
0111 = V.14 (reserved for RAM microcode)
1000 = BISYNC
1001 = DDCMP (reserved for RAM microcode)
1010 = Reserved
1011 = Reserved
1100 = Ethernet
11xx = Reserved
7.10.3 SCC Protocol-Specific Mode Register (PSMR)
The functionality of the SCC varies according to the protocol selected by the MODE bits in
the GSMR. Each of the four SCC has an additional 16-bit, memory-mapped, read-write
PSMR that configures the SCC to the special configurations within a chosen mode. A
detailed description of the PSMR bits is contained within each specific protocol. The PSMRs
are cleared at reset.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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