WM8352 datasheet(194/336 Pages) WOLFSON

Part #	WM8352

Description	Wolfson AudioPlus™ Stereo CODEC with Power Management

PDF	336 Pages

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Manufacturer	WOLFSON [Wolfson Microelectronics plc]

Direct Link	http://www.wolfsonmicro.com

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194 / 336 page

WM8352

Production Data

PD, February 2011, Rev 4.4

194

22.4 RTC GPIO OUTPUT

It is possible to configure GPIO6 as an RTC output, as described in Section 20. This output is a

square wave that is derived from the trimmed RTC counter. The frequency can be set to values

between 1Hz and 16.384kHz, as described in Table 136.

Note that, when RTC_TRIM is used to calibrate the crystal oscillator, the nominal 50% duty ratio of

this output may deviate by up to 8 clock periods of the 32.768kHz oscillator on the occasions when

the RTC Seconds Counter is increased (ie. once per second).

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

R23 (17h)

RTC Time

control

3:0

RTC_DSW [3:0]

0000

Divided Square wave select.

0000 = disabled

0001 = 1Hz

0010 = 2Hz

…

1011 = 1024Hz

1100 = 2048Hz

1101 = 4096Hz

1110 = 8192Hz

1111 = 16384Hz

Note: due to trim settings for crystal

intolerances a single square wave period

during seconds rollover may be decrease

its on time period or increase its off time

period by up to 8 32kHz periods.

Table 136 RTC GPIO Output

WM8352 Datasheet(PDF) 194 Page - Wolfson Microelectronics plc