Triple Timer Module
Triple Timer Module Programming Model
MOTOROLA
DSP56309UM/D 9-7
9.3.1
Prescaler Counter
The prescaler counter is a 21-bit counter that is decremented on the rising edge of the
prescaler input clock. The counter is enabled when at least one of the three timers is
enabled (i.e., one or more of the timer enable (TE) bits are set) and is using the prescaler
output as its source (i.e., one or more of the PCE bits are set).
9.3.2
Timer Prescaler Load Register (TPLR)
The TPLR is a 24-bit, read/write register that controls the prescaler divide factor (i. e.,
the number that the prescaler counter loads and begins counting from) and the source
for the prescaler input clock. The control bits are shown below in
9.3.2.1
TPLR Prescaler Preload Value (PL[20:0]) Bits 20-0
These 21 bits contain the prescaler preload value. This value is loaded into the prescaler
counter when the counter value reaches 0, or the counter switches state from disabled to
enabled.
If PL[20:0] = N, then the prescaler counts N + 1 source clock cycles before generating a
prescaler clock pulse. Therefore, the prescaler divide factor = (preload value) + 1.
The PL[20:0] bits are cleared by a hardware RESET signal or a software RESET
instruction.
9.3.2.2
TPLR Prescaler Source (PS[1:0]) Bits 22-21
The two PS bits control the source of the prescaler clock.
functionality. The prescalerÕs use of a TIO signal is not affected by the TCSR settings of
the timer corresponding to the TIO signal being used.
23
22
21
20
19
18
17
16
15
14
13
12
PS1
PS0
PL20
PL19
PL18
PL17
PL16
PL15
PL14
PL13
PL12
11
10
9
8
7
6
5
4
3
2
1
0
PL11
PL10
PL9
PL8
PL7
PL6
PL5
PL4
PL3
PL2
PL1
PL0
Ñ reserved, read as 0, should be written with 0 for future compatibility
Figure 9-4
Timer Prescaler Load Register (TPLR)
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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