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
Содержание DSP56309
Страница 25: ...xxii DSP56309UM D MOTOROLA Figure D 25 Port E Registers PCRE PRRE PDRE D 39 ...
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Страница 47: ...1 18 DSP56309UM D MOTOROLA DSP56309 Overview DSP56309 Architecture Overview ...
Страница 48: ...MOTOROLA DSP56309UM D 2 1 SECTION 2 SIGNAL CONNECTION DESCRIPTIONS ...
Страница 85: ...2 38 DSP56309UM D MOTOROLA Signal Connection Descriptions OnCE JTAG Interface ...
Страница 86: ...MOTOROLA DSP56309UM D 3 1 SECTION 3 MEMORY CONFIGURATION ...
Страница 104: ...MOTOROLA DSP56309UM D 4 1 SECTION 4 CORE CONFIGURATION ...
Страница 124: ...MOTOROLA DSP56309UM D 5 1 SECTION 5 GENERAL PURPOSE I O ...
Страница 125: ...5 2 DSP56309UM D MOTOROLA General Purpose I O 5 1 INTRODUCTION 5 3 5 2 PROGRAMMING MODEL 5 3 ...
Страница 128: ...MOTOROLA DSP56309UM D 6 1 SECTION 6 HOST INTERFACE HI08 ...
Страница 166: ...MOTOROLA DSP56309UM D 7 1 SECTION 7 ENHANCED SYNCHRONOUS SERIAL INTERFACE ESSI ...
Страница 212: ...MOTOROLA DSP56309UM D 8 1 SECTION 8 SERIAL COMMUNICATION INTERFACE SCI ...
Страница 241: ...8 30 DSP56309UM D MOTOROLA Serial Communication Interface SCI GPIO Signals and Registers ...
Страница 242: ...MOTOROLA DSP56309UM D 9 1 SECTION 9 TRIPLE TIMER MODULE ...
Страница 269: ...9 28 DSP56309UM D MOTOROLA Triple Timer Module Timer Operational Modes ...
Страница 270: ...MOTOROLA DSP56309UM D 10 1 SECTION 10 ON CHIP EMULATION MODULE ...
Страница 302: ...MOTOROLA DSP56309UM D 11 1 SECTION 11 JTAG PORT ...
Страница 369: ...C 22 DSP56309UM D MOTOROLA DSP56309 BSDL Listing ...
Страница 370: ...MOTOROLA DSP56309UM D D 1 APPENDIX D PROGRAMMING REFERENCE ...
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