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
Содержание DSP56309
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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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