9-22
DSP56309UM/D MOTOROLA
Triple Timer Module
Timer Operational Modes
This process is repeated until the timer is disabled (i.e., TE is cleared). If the counter
overflows, the TOF bit is set, and if TOIE is set, an overflow interrupt is generated. The
counter contents can be read at any time by reading the TCR.
9.4.2.3
Measurement Input Period (Mode 5)
In this mode, the timer counts the period between the reception of signal edges of the
same polarity across the TIO signal.
Set the TE bit to clear the counter and enable the timer. The value to which the timer is to
count is loaded into the TLR. The value of the INV bit determines whether the period is
measured between consecutive low-to-high (0 to 1) transitions of TIO or between
consecutive high-to-low (1 to 0) transitions of TIO. If INV is set, high-to-low signal
transitions are selected. If INV is cleared, low-to-high signal transitions are selected.
After the first appropriate transition occurs on the TIO input signal, the counter is
loaded with the TLR value on the first timer clock signal received from either the
DSP56309 clock divided by two (CLK/2) or the prescaler clock output. Each subsequent
clock signal increments the counter.
On the next signal transition of the same polarity that occurs on TIO, the TCF bit in the
TCSR is set and a compare interrupt is generated if the TCIE bit is set. The contents of the
counter are loaded into the TCR. The TCR then contains the value of the time that
elapsed between the two signal transitions on the TIO signal.
After the second signal transition, if the TRM bit is set, the TE bit is set to clear the
counter and enable the timer. The counter is loaded with the TLR value on the first timer
clock signal. Each subsequent clock signal increments the counter.
After the second signal transition, if the TRM bit is set, the TE bit is set to clear if the TRM
bit is cleared, the counter continues to be incremented on each timer clock. This process
is repeated until the timer is disabled (i.e., TE is cleared). If the counter overflows, the
TOF bit is set, and if TOIE is set, an overflow interrupt is generated. The counter contents
can be read at any time by reading the TCR.
Bit Settings
Mode Characteristics
TC3
TC2
TC1
TC0
Mode
Name
Function
TIO
Clock
0
1
0
1
5
Input Period
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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