BK3254 Datasheet

v 0.5

© 2011 Beken Corporation

Proprietary and Confidential

Page 10 of 17

3.

Functional Description

3.1.

GPIO

The BK3254 has total 22 GPIOs, which can be configured as either input or

output. Most of them have second function.

Table 1 GPIO Function Mapping

Name

Peripheral mode

GPIO Mode

GPIO0

UART_TXD/I2C_SCL

General I/O

GPIO1

UART_RXD/I2C_SDA

General I/O

GPIO2

TX_EN/USBP

General I/O

GPIO3

RX_EN/USBN

General I/O

GPIO4

ADC channel 1 input

General I/O

GPIO5

ADC channel 2 input

General I/O

GPIO6

SPI chip enable

General I/O

GPIO7

SPI clock or FLASH_WP

General I/O

GPIO8

SPI MOSI or FLASH_HD

General I/O

GPIO9

SPI MISO

General I/O

GPIO10

PWM0

General I/O

GPIO11

PWM1

General I/O

GPIO12

SD card clock

General I/O

GPIO13

SD card command

General I/O

GPIO14

SD card data (1-wire) or data bit 0 (4-wires)

General I/O

GPIO15

SD card data bit 1

General I/O

GPIO16

SD card data bit 2

General I/O

GPIO17

SD card data bit 3

General I/O

GPIO18

JTAG TCK

General I/O

GPIO19

JTAG TMS or ADC channel 3 input

General I/O

GPIO20

JTAG TDI

General I/O

GPIO21

JTAG TDO

General I/O

GPIO22

IrDA signal input

General I/O

All GPIO can be source to wake up MCU from shut down state. In shut down

state, any level change on the set GPIO will trigger the wake up procedure.

After power on, the GPIO0~GPIO6, GPIO9~GPIO17, and GPIO22 are non-in/out

with pull-low; GPIO7,GPIO8 is in second function mode; the GPIO18 to GPIO21

is JTAG mode.