Timer/Event Counter
Timer Modes of Operation
MOTOROLA
DSP56305 User’s Manual
9-23
9.4.2
Signal Measurement Modes
The following Signal Measurement modes are provided:
• Measurement Input Width
• Measurement Input Period
• Measurement Capture
9.4.2.1
Measurement Accuracy
The external signal is synchronized with the internal clock used to increment the
counter. This synchronization process can cause the number of clocks measured for the
selected signal value to vary from the actual signal value by plus or minus one counter
clock cycle.
9.4.2.2
Measurement Input Width (Mode 4)
In this mode, the timer counts the number of clocks that occur between opposite edges of
an input signal.
Set the TE bit to clear the counter and enable the timer. After the first appropriate
transition (as determined by the INV bit) occurs on the TIO input signal, the counter is
loaded with the TLR value on the first timer clock signal received either from the
DSP56305 clock divided by two (CLK/2) or from the prescaler clock input. Each
subsequent clock signal increments the counter.
In this mode the TIO signal acts as a gating signal for the internal timer clock. The TIO
polarity depends on the INV bit value. If the INV bit is set, the timer starts on the first
high-to-low (1 to 0) signal transition on the TIO signal. If the INV bit is cleared, the timer
starts on the first low-to-high (0 to 1) transition on the TIO signal.
When the first transition of opposite polarity to the INV bit occurs on the TIO signal, the
counter stops. The TCF bit in the TCSR is set, and if the TCIE bit is set, a compare
interrupt is generated. The value of the counter (which measures the width of the TIO
pulse) is loaded into the TCR. The TCR can be read to determine the external signal
pulse width. If the TRM bit is set, the counter is loaded with the TLR value on the first
Bit Settings
Mode Characteristics
TC3
TC2
TC1
TC0
Mode
Name
Kind
TIO
Clock
0
1
0
0
4
Input Width
Measurement
Input
Internal
Summary of Contents for DSP56305
Page 34: ...xxxii DSP56305 User s Manual MOTOROLA ...
Page 40: ...xxxvi DSP56305 User s Manual MOTOROLA ...
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 ...
Page 662: ...Y Index 12 DSP56305 User s Manual MOTOROLA ...