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Toshiba H1 SERIES TLCS-900 User Manual

Page 117

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TMP92CM22

2007-02-16

92CM22-115

In this mode, a programmable square wave is generated by inverting the timer output

each time the 8-bit up counter (UC0) matches the value in one of the timer registers
TA0REG or TA1REG.

The value set in TA0REG must be smaller than the value set in TA1REG.

Although the up counter for TMRA1 (UC1) is not used in this mode, TA01RUN
should be set to “1”, so that UC1 is set for counting.

Figure 3.7.14 shows a block diagram representing this mode.

Figure 3.7.14 Block Diagram of 8-Bit PPG Output Mode

If the TA0REG double buffer is enabled in this mode, the value of the register buffer will

be shifted into TA0REG each time TA1REG matches UC0.

Use of the double buffer facilitates the handling of low-duty waves (when duty is varied).

Figure 3.7.15 Operation of Register Buffer

Q

2

Q

1

Match with TA0REG

and UC0

Match withTA1REG

Q

3

Q

2

(Up counter = Q

2

)

(Up counter = Q

2

)

Shift into register buffer

Write TA0REG (Register buffer)

TA0REG (Value of compare)

Register buffer

8-bit

up counter

(UC0)

Comparator

Comparator

TA0IN

φT1
φT4

φT16

TA01MOD

TA1FF

TA0REG

Register buffer

TA1REG

TA01RUN

TA0REG-WR

TA01RUN

TA1OUT

TA1FFCR

INTTA0

INTTA1

Shift trigger

Internal data bus

Selector

Inversion

Selector

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