M32CSLASH8A datasheet(190/372 Pages) RENESAS

190 / 372 page

M32C/8A Group

15. Timers (Timer B)

Rev.1.00

Jul 15, 2007

Page 173 of 352

REJ09B0385-0100

15.2.1

Timer Mode

In timer mode, the timer counts an internally generated count source.

Table 15.9 lists specifications of timer mode. Figure 15.27 shows a timer mode operation (Timer B).

Table 15.9

Specifications of Timer Mode

NOTES:

1. Bits CNT3 to CNT0 in the TCSPR register select no division (n = 0) or divide-by-2n (n = 1 to 15).

2. Wait for one count source cycle or more to write after the count starts.

Figure 15.27

Operation in Timer Mode (Timer B)

Item

Specification

Count source

f1, f8, f2n(1), fC32

Count operation

• Counter decrements

When the timer underflows, the contents of the reload register are reloaded

into the counter and the count continues.

Counter cycle

n + 1

fj: count source frequency

n: setting value of the TBi register (i=0 to 5), 0000h to FFFFh

Count start condition

The TBiS bit in the TABSR or TBSR register is set to 1 (count starts)

Count stop condition

The TBiS bit is set to 0 (count stops)

Interrupt request generation timing When the timer underflows

TBiIN pin function

Programmable I/O port

Read from timer

A read from the TBi register returns a counter value.

Write to timer

• A write to the TBi register while the count is stopped:

The value is written to both the reload register and the counter.

• A write to the TBi register while counting:

The value is written to the reload register (It is transferred to the counter at the

next reload timing).(2)

Count starts

FFFFh

Count stops

i = 0 to 5

(Condition) TBiMR register: Bits TMOD1 and TMOD0 are set to 00b (timer mode).

TBiS bit in the

TABSR or TBSR

Contents of the counter

n = contents of the reload

0000h

IR bit in the TBiIC

Underflow

Reload

Underflow

Reload

Set to 0 by an interrupt request acknowledged or by program

Count resumes

M32C/8A датащи(PDF) 190 Page - Renesas Technology Corp

M32C/8A датащи(HTML) 190 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL