MC13191 Technical Data, Rev. 1.6

Freescale Semiconductor

13

8

Digital Input/ Output General Purpose Input/Output 4.

See Footnote 1

9

GPIO31

Digital Input/ Output General Purpose Input/Output 3.

See Footnote 1

10

GPIO21

Digital Input/ Output General Purpose Input/Output 2. When gpio_alt_en, Register

9, Bit 7 = 1, GPIO2 functions as a “CRC Valid” indicator.

See Footnote 1

11

GPIO11

Digital Input/ Output General Purpose Input/Output 1. When gpio_alt_en, Register

9, Bit 7 = 1, GPIO1 functions as an “Out of Idle” indicator.

See Footnote 1

12

RST

Digital Input

Active Low Reset. While held low, the IC is in Off Mode and all

internal information is lost from RAM and SPI registers. When

high, IC goes to IDLE Mode, with SPI in default state.

13

Digital Input

Active High. Low to high transition initiates RX or TX sequence

depending on SPI setting. Should be taken high after SPI

programming to start RX or TX sequence and should be held

high through the sequence. After sequence is complete, return

RXTXEN to low. When held low, forces Idle Mode.

See Footnote 2

14

ATTN2

Digital Input

Active Low Attention. Transitions IC from either Hibernate or

Doze Modes to Idle.

See Footnote 2

15

CLKO

Digital Output

Clock output to host MCU. Programmable frequencies of:

16 MHz, 8 MHz, 4 MHz, 2 MHz, 1 MHz, 62.5 kHz, 32.786+ kHz

(default), and 16.393+ kHz.

16

SPICLK2

Digital Clock Input

External clock input for the SPI interface.

See Footnote 2

17

MOSI2

Digital Input

Master Out/Slave In. Dedicated SPI data input.

See Footnote 2

18

Digital Output

Master In/Slave Out. Dedicated SPI data output.

See Footnote 3

19

CE2

Digital Input

Active Low Chip Enable. Enables SPI transfers.

See Footnote 2

20

IRQ

Digital Output

Active Low Interrupt Request.

Open drain device.

internal pull-up.

Interrupt can be

serviced every 6 µs

with <20 pF load.

Optional external

21

VDDD

Power Output

Digital regulated supply bypass.

Decouple to ground.

22

VDDINT

Power Input

Digital interface supply & digital regulator input. Connect to

Battery.

2.0 to 3.4 V. Decouple

to ground.

23

GPIO51

Digital Input/Output General Purpose Input/Output 5.

See Footnote 1

24

GPIO61

Digital Input/Output General Purpose Input/Output 6.

See Footnote 1

25

GPIO71

Digital Input/Output General Purpose Input/Output 7.

See Footnote 1

26

XTAL1

Input

Crystal Reference oscillator input.

Connect to 16 MHz

crystal and load

capacitor.

Table 8. Pin Function Description (continued)

Pin # Pin Name

Type

Description

Functionality