7-36
DSP56309UM/D MOTOROLA
Enhanced Synchronous Serial Interface (ESSI)
Operating Modes
When the RSMA or RSMB register are read by the internal data bus, the register contents
occupy the two low-order bytes of the data bus, and the high-order byte is zero-filled.
After a hardware RESET signal or a software RESET instruction, the RSM register is reset
to $FFFFFFFF; this setting enables all thirty-two time slots for data transmission.
7.5
OPERATING MODES
The ESSI operating modes are selected by the ESSI control registers (CRA and CRB). The
operating modes are described in the following paragraphs.
7.5.1
ESSI After Reset
A hardware RESET signal or software RESET instruction clears the port control register
and the port direction control register. This situation configures all the ESSI signals as
GPIO. The ESSI is in the reset state while all ESSI signals are programmed as GPIO; the
ESSI is active only if at least one of the ESSI I/O signals is programmed as an ESSI signal.
7.5.2
ESSI Initialization
To initialize the ESSI, do the following:
1. Send a reset: a hardware RESET signal, software RESET instruction, ESSI
individual reset, or STOP instruction.
2. Program the ESSI control and time slot registers.
3. Write data to all the enabled transmitters.
4. Configure at least one signal as an ESSI signal.
5. If an external frame sync is used, from the moment the ESSI is activated, at least
five serial clocks are needed before the first external frame sync is supplied.
Otherwise, improper operation can result.
Clearing the PC[5:0] bits in the GPIO PCR during program execution causes the ESSI to
stop serial activity and enter the individual reset state. All status bits of the interface are
set to their reset state. The contents of CRA and CRB are not affected. The ESSI
individual reset allows a program to reset each interface separately from the other
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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