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DSP56305 User’s Manual
MOTOROLA
Enhanced Synchronous Serial Interface (ESSI)
ESSI Programming Model
7.4.2
ESSI Control Register B (CRB)
The CRB is one of two 24-bit read/write control registers used to direct the operation of
the ESSI (see Figure 7-7). CRB controls the ESSI multifunction signals, SC[2:0], which can
be
used as clock inputs or outputs, frame synchronization signals, transmit data signals,
or serial I/O flag signals.
The serial output flag control bits and the direction control bits for the serial control
signals are in the ESSI CRB. Interrupt enable bits for the receiver and the transmitter are
also in the CRB. The bit setting of the CRB also determines how many transmitters are
enabled (0, 1, 2, or 3 transmitters can be enabled). The CRB settings also determine the
ESSI operating mode.
Either a hardware reset signal or a software reset instruction clear all the bits in the CRB.
The relationship between the ESSI signals SC[2:0], SCK, and the CRB bits is summarized
in Table 7-4. See also Figure 7-3, Figure 7-4, Figure 7-5, and Figure 7-15. The ESSI CRB
bits are described in the following paragraphs.
7.4.2.1
Serial Output Flags (OF[1:0]) CRB Bits 1-0
The ESSI has two serial output flag bits, OF1 and OF0. The normal sequence for setting
output flags when transmitting data (by transmitter 0 through the STD signal only) is:
1. Wait for TDE (TX0 empty) to be set.
2. Write the flags.
3. Write the transmit data to the TX register.
Bits OF0 and OF1 are double-buffered so that the flag states appear on the signals when
the TX data is transferred to the Transmit Shift Register. The flag bits values are
synchronized with the data transfer.
Note:
The timing of the optional serial output signals SC[2:0] is controlled by the
frame timing and is not affected by the settings of TE2, TE1, TE0, or the
Receive Enable (RE) bit of the CRB.
7.4.2.1.1
Serial Output Flag 0 (OF0) CRB Bit 0
When the ESSI is in Synchronous mode and transmitter 1 is disabled (TE1 = 0), the SC0
signal is configured as ESSI flag 0. If the serial control direction bit (SCD0) is set, the SC0
signal is an output. Data present in bit OF0 is written to SC0 at the beginning of the
frame in Normal mode or at the beginning of the next time slot in Network mode.
Bit OF0 is cleared by a hardware reset signal or by a software reset instruction.
Summary of Contents for DSP56305
Page 34: ...xxxii DSP56305 User s Manual MOTOROLA ...
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Page 41: ...MOTOROLA DSP56305 User s Manual 1 1 SECTION 1 DSP56305 OVERVIEW ...
Page 58: ...1 18 DSP56305 User s Manual MOTOROLA DSP56305 Overview DSP56305 Architecture Overview ...
Page 59: ...MOTOROLA DSP56305 User s Manual 2 1 SECTION 2 SIGNAL CONNECTION DESCRIPTIONS ...
Page 98: ...2 40 DSP56305 User s Manual MOTOROLA Signal Connection Descriptions JTAG OnCE Interface ...
Page 99: ...MOTOROLA DSP56305 User s Manual 3 1 SECTION 3 MEMORY CONFIGURATION ...
Page 119: ...MOTOROLA DSP56305 User s Manual 4 1 SECTION 4 CORE CONFIGURATION ...
Page 144: ...4 26 DSP56305 User s Manual MOTOROLA Core Configuration JTAG Boundary Scan Register BSR ...
Page 145: ...MOTOROLA DSP56305 User s Manual 5 1 SECTION 5 GENERAL PURPOSE I O ...
Page 149: ...HOST INTERFACE HI32 MOTOROLA DSP56305 User s Manual 6 1 SECTION 6 HOST INTERFACE HI32 ...
Page 150: ...6 2 DSP56305 User s Manual MOTOROLA HOST INTERFACE HI32 ...
Page 259: ...MOTOROLA DSP56305 User s Manual 7 1 SECTION 7 ENHANCED SYNCHRONOUS SERIAL INTERFACE ESSI ...
Page 315: ...MOTOROLA DSP56305 User s Manual 8 1 SECTION 8 SERIAL COMMUNICATION INTERFACE SCI ...
Page 347: ...MOTOROLA DSP56305 User s Manual 9 1 SECTION 9 TIMER EVENT COUNTER ...
Page 376: ...9 30 DSP56305 User s Manual MOTOROLA Timer Event Counter Timer Modes of Operation ...
Page 377: ...MOTOROLA DSP56305 User s Manual 10 1 SECTION 10 ON CHIP EMULATION MODULE ...
Page 411: ...MOTOROLA DSP56305 User s Manual 11 1 SECTION 11 JTAG PORT ...
Page 430: ...11 20 DSP56305 User s Manual MOTOROLA JTAG Port DSP56305 Boundary Scan Register ...
Page 431: ...Filter Co Processor MOTOROLA DSP56305 User s Manual 12 1 SECTION 12 FILTER CO PROCESSOR ...
Page 471: ...VITERBI CO PROCESSOR MOTOROLA DSP56305 User s Manual 13 1 SECTION 13 VITERBI CO PROCESSOR ...
Page 522: ...13 52 DSP56305 User s Manual MOTOROLA VITERBI CO PROCESSOR References ...
Page 554: ...14 32 DSP56305 User s Manual MOTOROLA CYCLIC CODE CO PROCESSOR Configuration Examples ...
Page 555: ...MOTOROLA DSP56305 User s Manual A 1 APPENDIX A BOOTSTRAP CODE ...
Page 568: ...A 14 DSP56305 User s Manual MOTOROLA Bootstrap Code ...
Page 569: ...Equates MOTOROLA DSP56305 User s Manual B 1 APPENDIX B EQUATES ...
Page 589: ...MOTOROLA DSP56305 User s Manual C 1 APPENDIX C JTAG BSDL ...
Page 590: ...C 2 DSP56305 User s Manual MOTOROLA JTAG BSDL ...
Page 600: ...C 12 DSP56305 User s Manual MOTOROLA JTAG BSDL ...
Page 601: ...MOTOROLA DSP56305 User s Manual D 1 APPENDIX D PROGRAMMING REFERENCE ...
Page 602: ...D 2 DSP56305 User s Manual MOTOROLA PROGRAMMING REFERENCE ...
Page 661: ...Y MOTOROLA DSP56305 User s Manual Index 11 ...
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