User's Manual

consists of six programmable, bi-directional I/O lines, PIO[2:7].

Programmable I/O lines can be accessed either via an embedded application running on

WT11 or via private channel or manufacturer-specific HCI commands.

All PIO lines are configured as inputs with weak pull downs at reset.

PIO[2] / USB_PULL_UP (1)

This is a multifunction terminal. The function depends on whether WT11 is a USB or UART

capable version. On UART versions, this terminal is a programmable I/O. On USB versions,

it can drive a pull-up resistor on USB_D+. For application using external RAM this terminal

may be programmed for chip select.

PIO[3] / USB_WAKE_UP (1)

This is a multifunction terminal. On UART versions of WT11 this terminal is a

programmable I/O. On USB versions, its function is selected by setting the Persistent

Store Key PSKEY_USB_PIO_WAKEUP (0x2cf) either as a programmable I/O or as a

USB_WAKE_UP function.

PIO[4] / USB_ON (1)

This is a multifunction terminal. On UART versions of WT11 this terminal is a

programmable I/O. On USB versions, the USB_ON function is also selectable.

PIO[5] / USB_DETACH (1)

This is a multifunction terminal. On UART versions of WT11 this terminal is a

programmable I/O. On USB versions, the USB_DETACH function is also selectable.

PIO[6] / CLK_REQ

This is multifunction terminal, its function is determined by Persistent Store Keys. Using

PSKEY_CLOCK_REQUEST_ENABLE, (0x246) this terminal can be configured to be low

when WT11 is in deep sleep and high when a clock is required. The clock must be supplied

within 4ms of the rising edge of PIO[6] to avoid losing timing accuracy in certain Bluetooth

operating modes.

PIO[7]

Programmable I/O terminal.

8. RESET

The RESET pin is an active high reset and is internally filtered using the internal low

frequency clock oscillator. A reset will be performed between 1.5 and 4.0ms following

RESET being active. It is recommended that RESET be applied for a period greater than

5ms.