Signal/Connection Descriptions
External Memory Expansion Port (Port A)
MOTOROLA
DSP56309UM/D 2-11
TA
Input
Ignored
Input
Transfer Acknowledge
ÑIf the DSP56309 is the bus
master and there is no external bus activity, or the
DSP56309 is not the bus master, the TA input is
ignored. The TA input is a data transfer
acknowledge (DTACK) function that can extend an
external bus cycle indefinitely. Any number of wait
states (1, 2,..., infinity) can be added to the wait states
inserted by the BCR by keeping TA deasserted. In
typical operation, TA is deasserted at the start of a
bus cycle, is asserted to enable completion of the bus
cycle, and is deasserted before the next bus cycle.
The current bus cycle completes one clock period
after TA is asserted synchronous to CLKOUT. The
number of wait states is determined by the TA input
or by the BCR, whichever is longer. The BCR can be
used to set the minimum number of wait states in
external bus cycles.
In order to use the TA functionality, the BCR must be
programmed to at least one wait state. A zero wait
state access cannot be extended by TA deassertion;
otherwise, improper operation can result. TA can
operate synchronously or asynchronously
depending on the setting of the TAS bit in the OMR.
You must not use TA functionality while performing
DRAM type accesses; otherwise, improper operation
can result.
Table 2-8
External Bus Control Signals (Continued)
Signal
Name
Type
State
During
Reset
Signal Description
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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