Triple Timer Module
Timer Operational Modes
MOTOROLA
DSP56309UM/D 9-21
¥ 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. Load the timerÕs count value into
the TLR. 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 DSP56309 clock divided by two (CLK/2) or from the
prescaler clock input. Each subsequent clock signal increments the counter.
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 opposite in polarity to the INV bit setting occurs on the TIO
signal, the counter stops. The TCF bit in the TCSR is set and a compare interrupt is
generated if the TCIE bit is set. 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 timer clock
received following the next valid transition occurring on the TIO input signal and the
count is resumed. If the TRM bit is cleared, the counter continues to be incremented on
each timer clock.
Bit Settings
Mode Characteristics
TC3
TC2
TC1
TC0
Mode
Name
Function
TIO
Clock
0
1
0
0
4
Input Width
Measurement
Input
Internal
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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