7-22
DSP56309UM/D MOTOROLA
Enhanced Synchronous Serial Interface (ESSI)
ESSI Programming Model
7.4.2.13
Enabling, Disabling ESSI Data Transmission
The ESSI has three transmit enable bits (TE[2:0]), one for each data transmitter. The
process of transmitting data from TX1 and TX2 is the same. TX0 can also operate in
asynchronous mode. The normal transmit enable sequence is to write data to one or
more transmit data registers (or the time slot register (TSR)) before setting the TE bit. The
normal transmit disable sequence is to clear the TE, transmit interrupt enable (TIE), and
transmit exception interrupt enable (TEIE) bits after the transmit data empty (TDE) bit is
set. In network mode, clearing the appropriate TE bit and setting it again disables the
corresponding transmitter (0, 1, or 2) after transmission of the current data word. The
transmitter remains disabled until the beginning of the next frame. During that time
period, the corresponding SC (or STD in the case of TX0) signal remains in the
high-impedance state.
7.4.2.14
CRB ESSI Transmit 2 Enable (TE2) Bit 14
The TE2 bit enables the transfer of data from TX2 to transmit shift register 2. TE2 is
functional only when the ESSI is in synchronous mode and is ignored when the ESSI is
in asynchronous mode.
When TE2 is set and a frame sync is detected, transmitter 2 is enabled for that frame.
When TE2 is cleared, transmitter 2 is disabled after completing transmission of data
currently in the ESSI transmit shift register. Any data present in TX2 is not transmitted. If
TE2 is cleared, data can be written to TX2; the TDE bit is cleared, but data is not
transferred to transmit shift register 2.
Figure 7-14
Normal Mode, External Frame Sync (8 Bit, 1 Word in Frame)
Frame SYNC
(FSL0 = 0, FSL1 = 0)
Frame SYNC
(FSL0 = 0, FSL1 = 1)
Data Out
Flags
Slot 0
Slot 0
Wait
AA0684
Summary of Contents for DSP56309
Page 25: ...xxii DSP56309UM D MOTOROLA Figure D 25 Port E Registers PCRE PRRE PDRE D 39 ...
Page 30: ...MOTOROLA DSP56309UM D 1 1 SECTION 1 DSP56309 OVERVIEW ...
Page 47: ...1 18 DSP56309UM D MOTOROLA DSP56309 Overview DSP56309 Architecture Overview ...
Page 48: ...MOTOROLA DSP56309UM D 2 1 SECTION 2 SIGNAL CONNECTION DESCRIPTIONS ...
Page 85: ...2 38 DSP56309UM D MOTOROLA Signal Connection Descriptions OnCE JTAG Interface ...
Page 86: ...MOTOROLA DSP56309UM D 3 1 SECTION 3 MEMORY CONFIGURATION ...
Page 104: ...MOTOROLA DSP56309UM D 4 1 SECTION 4 CORE CONFIGURATION ...
Page 124: ...MOTOROLA DSP56309UM D 5 1 SECTION 5 GENERAL PURPOSE I O ...
Page 125: ...5 2 DSP56309UM D MOTOROLA General Purpose I O 5 1 INTRODUCTION 5 3 5 2 PROGRAMMING MODEL 5 3 ...
Page 128: ...MOTOROLA DSP56309UM D 6 1 SECTION 6 HOST INTERFACE HI08 ...
Page 166: ...MOTOROLA DSP56309UM D 7 1 SECTION 7 ENHANCED SYNCHRONOUS SERIAL INTERFACE ESSI ...
Page 212: ...MOTOROLA DSP56309UM D 8 1 SECTION 8 SERIAL COMMUNICATION INTERFACE SCI ...
Page 241: ...8 30 DSP56309UM D MOTOROLA Serial Communication Interface SCI GPIO Signals and Registers ...
Page 242: ...MOTOROLA DSP56309UM D 9 1 SECTION 9 TRIPLE TIMER MODULE ...
Page 269: ...9 28 DSP56309UM D MOTOROLA Triple Timer Module Timer Operational Modes ...
Page 270: ...MOTOROLA DSP56309UM D 10 1 SECTION 10 ON CHIP EMULATION MODULE ...
Page 302: ...MOTOROLA DSP56309UM D 11 1 SECTION 11 JTAG PORT ...
Page 369: ...C 22 DSP56309UM D MOTOROLA DSP56309 BSDL Listing ...
Page 370: ...MOTOROLA DSP56309UM D D 1 APPENDIX D PROGRAMMING REFERENCE ...
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