9-20
DSP56309UM/D MOTOROLA
Triple Timer Module
Timer Operational Modes
9.4.1.4
Timer Event Counter (Mode 3)
In this mode, the timer counts external events and issues an interrupt when a preset
number of events is counted.
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 TPCR. The counter is loaded with the TLR value when the first
timer clock signal is received. The timer clock signal can be taken from either the TIO
input signal or the prescaler clock output. Each subsequent clock signal increments the
counter. If an external clock is used, it must be internally synchronized to the internal
clock, and its frequency must be less than the DSP56309 internal operating frequency
divided by 4.
The value of the INV bit in the TCSR determines whether low-to-high (0 to 1) transitions
or high-to-low (1 to 0) transitions increment the counter. If the INV bit is set, high-to-low
transitions increment the counter. If the INV bit is cleared, low-to-high transitions
increment the counter.
When the counter matches the value contained in the TCPR, the TCF bit in the TCSR is
set, and a compare interrupt is generated if the TCIE bit is set. If the TRM bit is set, the
counter is loaded with the value of the TLR when the next timer clock is received, and
the count is resumed. 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.
9.4.2
Signal Measurement Modes
The following Signal Measurement modes are provided:
¥ Measurement input width
Bit Settings
Mode Characteristics
TC3
TC2
TC1
TC0
TIO
Clock
#
Function
Name
0
0
1
1
Input
External
3
Timer
Event Counter
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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