R8CSLASH20 datasheet(168/501 Pages) RENESAS

168 / 501 page

R8C/20 Group, R8C/21 Group

14. Timers

Rev.2.00 Aug 27, 2008

Page 152 of 458

REJ09B0250-0200

NOTES:

1. The set value is reflected at the following one-shot pulse after writing to registers TRBSC and

TRBPR.

2. Do not set both the TRBPRE and TRBPR registers to 00h.

Table 14.10

Programmable Wait One-Shot Generation Mode Specifications

Item

Specification

Count Sources

f1, f2, f8, timer RA underflow

Count Operations

• Decrement the setting value in timer RB primary

• When a count of timer RB primary underflows, the timer reloads the

contents of the timer RB secondary before the count continues.

• When a count of timer RB secondary underflows, the timer reloads the

contents of the timer RB primary before the count completes and the

TOSSTF bit is set to 0 (one-shot stops).

• When a count stops, the timer reloads the contents of the reload register

before it stops.

Wait Time

(n+1)(m+1)/fi

fi: Count source frequency

n: Setting value in the TRBPRE register, m: Setting value in the TRBPR register(2)

One-Shot Pulse Output Time (n+1)(p+1)/fi

fi: Count source frequency

n: Setting value in the TRBPRE register, p: Setting value in the TRBSC register

Count Start Conditions

• The TSTART bit in the TRBCR register is set to 1 (count starts) and the

next trigger is generated.

• Set the TOSST bit in the TRBOCR register to 1 (one-shot starts)

• Input trigger to the INT0 pin

Count Stop Conditions

• When reloading completes after timer RB underflows during secondary period

• When the TOSSP bit in the TRBOCR register is set to 0 (one-shot stops)

• When the TSTART bit in the TRBCR register is set to 0 (starts counting)

• When the TSTOP bit in the TRBCR register is set to 1 (forcibly stops

counting)

Interrupt Request

Generation Timing

In half cycles of the count source after timer RB underflows during

secondary period (complete at the same time as waveform output from the

TRBO pin) [timer RB interrupt]

TRBO Pin Function

Pulse output

INT0 Pin Functions

• When the INOSTG bit in the TRBIOC register is set to 0 (INT0 one-shot

trigger disabled), programmable I/O port or INT0 interrupt input

• When the INOSTG bit in the TRBIOC register is set to 1 (INT0 one-shot

trigger enabled), external trigger (INT0 interrupt input)

Read from Timer

The count value can be read out by reading the TRBPR and TRBPRE

registers.

Write to Timer

• When registers TRBPRE, TRBSC, and TRBPR are written while the

count stops, values are written to both the reload register and counter.

• When registers TRBPRE, TRBSC, and TRBPR are written to during

count operation, values are written to the reload registers only.(1)

Select Functions

• Output level select function

The TOPL bit in the TRBIO register can select the output level of the

one-shot pulse waveform.

• One-shot trigger select function

Refer to 14.2.3.1 One-Shot Trigger Selection.

R8C/20 Datasheet(PDF) 168 Page - Renesas Technology Corp

R8C/20 Datasheet(HTML) 168 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

Datasheet Download

Link URL