Motorola DSP56301 ユーザーズマニュアル
ESSI Data and Control Signals
Enhanced Synchronous Serial Interface (ESSI)
7
-5
When configured as an output,
SC1
functions as a serial Output Flag, as the transmitter 0
drive-enabled signal, or as the receive frame sync signal output. If
SC1
is used as serial
Output Flag 1, its value is determined by the value of the serial Output Flag 1 (OF1) bit in the
CRB. When configured as an input, this signal can receive frame sync signals from an
external source, or it acts as a serial input flag. As a serial input flag, SC1controls status bit
IF1 in the SSISR.
CRB. When configured as an input, this signal can receive frame sync signals from an
external source, or it acts as a serial input flag. As a serial input flag, SC1controls status bit
IF1 in the SSISR.
When
SC1
is configured as a transmit data signal, it is always an output signal, regardless of
the SCD1 bit value. As an output, it is fully synchronized with the other ESSI transmit data
signals (
signals (
STD
and
SC0
).
SC1
can be programmed as a GPIO signal (P1) when the ESSI
SC1
function is not in use.
Table 7-2. Mode and Signal Definitions
Control Bits
ESSI Signals
SYN
TE0
TE1
TE2
RE
SC0
SC1
SC2
SCK
STD
SRD
0
0
X
X
0
U
U
U
U
U
U
0
0
X
X
1
RXC
FSR
U
U
U
RD
0
1
X
X
0
U
U
FST
TXC
TD0
U
0
1
X
X
1
RXC
FSR
FST
TXC
TD0
RD
1
0
0
0
0
U
U
U
U
U
U
1
0
0
0
1
F0/U
F1/T0D/U
FS
XC
U
RD
1
0
0
1
0
F0/U
TD2
FS
XC
U
U
1
0
0
1
1
F0/U
TD2
FS
XC
U
RD
1
0
1
0
0
TD1
F1/T0D/U
FS
XC
U
U
1
0
1
0
1
TD1
F1/T0D/U
FS
XC
U
RD
1
0
1
1
0
TD1
TD2
FS
XC
U
U
1
0
1
1
1
TD1
TD2
FS
XC
U
RD
1
1
0
0
0
F0/U
F1/T0D/U
FS
XC
TD0
U
1
1
0
0
1
F0/U
F1/T0D/U
FS
XC
TD0
RD
1
1
0
1
0
F0/U
TD2
FS
XC
TD0
U
1
1
0
1
1
F0/U
TD2
FS
XC
TD0
RD
1
1
1
0
0
TD1
F1/T0D/U
FS
XC
TD0
U
1
1
1
0
1
TD1
F1/T0D/U
FS
XC
TD0
RD
1
1
1
1
0
TD1
TD2
FS
XC
TD0
U
1
1
1
1
1
TD1
TD2
FS
XC
TD0
RD
TXC
=
Transmitter clock
RXC
=
Receiver clock
XC
=
Transmitter/receiver clock (synchronous operation)
FST
=
Transmitter frame sync
FSR
=
Receiver frame sync
FS
=
Transmitter/receiver frame sync (synchronous operation)
TD0
=
Transmit data signal 0
TD1
=
Transmit data signal 1
TD2
=
Transmit data signal 2
T0D
=
Transmitter 0 drive enable if SSC1 = 1 & SCD1 = 1
RD
=
Receive data
F0
=
Flag 0
F1
=
Flag 1 if SSC1 = 0
U
=
Unused (can be used as GPIO signal)
X
=
Indeterminate