ADIS16445SLASHPCBZ datasheet(16/22 Pages) AD

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ADIS16445

Data Sheet

Rev. F | Page 16 of 22

INPUT/OUTPUT CONFIGURATION

DATA READY INDICATOR

The data ready indicator provides a signal that indicates

when the registers are updating, so that system processors can

avoid data collision, a condition when internal register updates

happen at the same time that an external processor requests it.

The data ready signal has valid and invalid states. Using the

transition from invalid to valid to trigger an interrupt service

routine provides the most time for data acquisition (before

the next register update). See Figure 4 and Table 2 for specific

timing information.

MSC_CTRL[2:0] (see Table 24) provide control bits for ena-

bling this function, selecting the polarity of the valid state and

I/O line assignment (DIO1, DIO2). The factory default setting

of MSC_CTRL[2:0] = 110 establishes DIO1 as a data ready out-

put line and assigns the valid state with a logic high (1). Set

MSC_CTRL[2:0] = 100 (DIN = 0xB404) to change the polarity of

the data ready signal on DIO1 for interrupt inputs that require

negative logic inputs for activation.

GENERAL-PURPOSE INPUT/OUTPUT

DIO1, DIO2, DIO3, and DIO4 are configurable, general-purpose

input/output lines that serve multiple purposes. The data

ready controls in MSC_CTRL[2:0] have the highest priority

for configuring DIO1 and DIO2. The alarm indicator controls in

ALM_CTRL[2:0] have the second highest priority for configuring

DIO1 and DIO2. The external clock control associated with

SMPL_PRD[0] has the highest priority for DIO4 configuration

(see Table 28). GPIO_CTRL in Table 27 has the lowest priority

for configuring DIO1, DIO2, and DIO4, and has absolute con-

trol over DIO3.

Table 27. GPIO_CTRL (Base Address = 0x32), Read/Write

Bits

Description (Default = 0x0000)

[15:12]

Not used

General-Purpose I/O Line 4 (DIO4) data level

General-Purpose I/O Line 3 (DIO3) data level

General-Purpose I/O Line 2 (DIO2) data level

General-Purpose I/O Line 1 (DIO1) data level

[7:4]

Not used

General-Purpose I/O Line 4 (DIO4) direction control

1 = output, 0 = input

General-Purpose I/O Line 3 (DIO3) direction control

1 = output, 0 = input

General-Purpose I/O Line 2 (DIO2) direction control

1 = output, 0 = input

General-Purpose I/O Line 1 (DIO1) direction control

1 = output, 0 = input

Example Input/Output Configuration

For example, set GPIO_CTRL[3:0] = 0100 (DIN = 0xB204)

to set DIO3 as an output signal pin and DIO1, DIO2, and

DIO4 as input signal pins. Set the output on DIO3 to 1 by set-

ting GPIO_CTRL[10] = 1 (DIN = 0xB304). Then, read

GPIO_CTRL[7:0] (DIN = 0x3200) and mask off GPIO_CTRL[9:8]

and GPIO_CTRL[11] to monitor the digital signal levels on

DIO4, DIO2, and DIO1.

ADIS16445/PCBZ Datasheet(PDF) 16 Page - Analog Devices

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