WM8321 datasheet(46/253 Pages) WOLFSON

46 / 253 page

WM8321

Production Data

PD, February 2012, Rev 4.0

The WM8321 provides two interrupt flags associated with the crystal oscillator, as described in

Section 13.2. These interrupts will provide indication of a crystal oscillator start-up failure, or detection

of an interruption to the crystal oscillator (eg, due to tampering).

The CLKOUT control fields are described in Table 16. Some of these controls may also be stored in

the integrated OTP memory. See Section 14 for details.

The 32.768kHz oscillator may also be output on a GPIO pin, as described in Section 21. Note that a

GPIO pin configured as 32.768kHz output will continue to output the oscillator clock in the OFF power

state; this may be used to provide clocking to the processor in the OFF state, provided that the

selected power domain for that GPIO pin remains enabled in the OFF state. The CLKOUT output is

always disabled in the OFF power state.

The internal RC oscillator generates the required clocks for the integrated DC-DC Converters on the

WM8321. Note that a 2MHz ‘External Power Clock’, derived from this oscillator, may be output on a

GPIO pin to provide synchronised clocking of external DC-DC Converters if required (see Section 21).

The 2MHz External Power Clock is only enabled when either of the External Power Enable signals

EPE1 or EPE2 is asserted. The External Power Enable (EPE) signals are controlled as described in

Section 15.3.

Note that the CLKOUT_ENA control register is locked by the WM8321 User Key. This register can

only be changed by writing the appropriate code to the Security register, as described in Section 12.4.

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

R16397 (400Dh)

System Status

XTAL_OK

Crystal Oscillator Status

0 = Disabled or in start-up phase

1 = Enabled and verified

R16528 (4090h)

Clock Control 1

CLKOUT_ENA

CLKOUT output enable

0 = Disabled

1 = Enabled

Protected by user key

CLKOUT_OD

CLKOUT pin configuration

0 = CMOS

1 = Open Drain

10:8

CLKOUT_SLOT

000

CLKOUT output enable ON slot

select

000 = Do not enable

001 = Enable in Timeslot 1

010 = Enable in Timeslot 2

011 = Enable in Timeslot 3

100 = Enable in Timeslot 4

101 = Enable in Timeslot 5

110 = Do not enable

111 = Do not enable

6:4

CLKOUT_SLP

SLOT

000

CLKOUT output SLEEP slot select

000 = Controlled by CLKOUT_ENA

001 = Disable in Timeslot 5

010 = Disable in Timeslot 4

011 = Disable in Timeslot 3

100 = Disable in Timeslot 2

101 = Disable in Timeslot 1

110 = Controlled by CLKOUT_ENA

111 = Controlled by CLKOUT_ENA

WM8321 数据表(PDF) 46 Page - Wolfson Microelectronics plc

WM8321 数据表(HTML) 46 Page - Wolfson Microelectronics plc

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

数据表下载