9-26
DSP56309UM/D MOTOROLA
Triple Timer Module
Timer Operational Modes
If the counter overflows, the TOF bit is set, and if TOIE is set, an overflow interrupt is
generated. At the same time, a pulse is output on the TIO signal with a pulse width equal
to the timer clock period. The pulse polarity is determined by the value of the INV bit. If
the INV bit is set, the pulse polarity is high (logical 1). If the INV bit is cleared, the pulse
polarity is low (logical 0).
The counter contents can be read at any time by reading the TCR. The counter is
reloaded whenever the TLR is written with a new value while the TE bit is set.
Note:
In this mode, internal logic preserves the TIO value and direction for an
additional 2.5 internal clock cycles after a DSP56309 hardware RESET signal is
asserted. This insures that a valid RESET signal is generated when the TIO
signal is used to reset the DSP56309.
9.4.4.2
Watchdog Toggle (Mode 10)
In this mode, the timer toggles an external signal after preset period.
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 on the first
timer clock received from either the DSP56309 internal clock divided by two (CLK/2) or
the prescaler clock output. Each subsequent timer clock increments the counter. The TIO
signal is set to the value of the INV bit.
When the counter equals the value in the TCPR, the TCF bit in the TCSR is set, and a
compare interrupt is generated if the TCIE bit is also set. If the TRM bit is set, the counter
is loaded with the TLR value on the next timer clock and the count is resumed. If the
TRM bit is cleared, the counter continues to be incremented on each subsequent timer
clock.
When counter overflow has occurred, the polarity of the TIO output signal is inverted,
the TOF bit in the TCSR is set, and an overflow interrupt is generated if the TOIE bit is
also set. The TIO polarity is determined by the INV bit.
The counter is reloaded whenever the TLR is written with a new value while the TE bit is
set. This process is repeated until the timer is disabled by clearing the TE bit. The counter
contents can be read at any time by reading the TCR register.
Bit Settings
Mode Characteristics
TC3
TC2
TC1
TC0
Mode
NAME
Function
TIO
Clock
1
0
1
0
10
Toggle
Watchdog
Output
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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