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Timer_b, Chapter 11 – Texas Instruments MSP430x1xx User Manual

Page 177

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11-1

Timer_B

Timer_B

This section describes the basic functions of the MSP430 general-purpose
16-bit Timer_B. Timer_B implementation differs among MSP430 devices.
Always check the device’s data sheet to determine the connections and the
number of identical capture/compare registers. Also, the data sheets use
additional nomenclature to indicate the number of capture/compare registers
implemented for a specific device. For example, if

Timer_B3 is discussed in

a data sheet, then that device’s implementation of Timer_B contains 3
capture/compare registers.

In its default condition, Timer_B operates identically to Timer_A, except the
SCCI bit is not implemented on Timer_B.

Note:

Throughout this chapter, the word

count is used in the text. As used in these

instances, it refers to the literal act of counting. It means that the counter must
be in the process of counting for the action to take place. If a particular value
is directly written to the counter, then the associated action will not take place.
For example, the CCR0 interrupt flag is set when the timer

counts up to the

value in CCR0 compare latch TBCL0. The counter

must count from

TBCL0 –1 to TBCL0. If the TBCL0 value were simply written directly to the
timer with software, the interrupt flag would

not be set, even though the val-

ues in the timer and TBCL0 would be the same.

Topic

Page

11.1 Introduction

11-2

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11.2 Timer_B Operation

11-5

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11.3 Timer Modes

11-8

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11.4 Capture/Compare Blocks

11-15

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11.5 The Output Unit

11-23

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11.6 Timer_B Registers

11-29

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 11