Application Interface; Serial Interface - TDK Module blu2i User Manual

Tdk module user guide

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Application Interface

The blu

Module is equipped with a 40-pin 0.5mm pitch board to board

connector that connects to the application platform. Electrical and

mechanical characteristics of the board-to-board connector are specified

in Chapter 3.

• Serial interface (see Section 3.0)

• Electrical specification of the interface (see Section 3.1)

UART_TX, UART_RX, UART_RTS and UART_CTS form a conventional

asynchronous serial data port. The interface is designed to operate

correctly when connected to other UART devices such as the 16550A.

The signalling levels are nominal 0V and 3.3V and are inverted with

respect to the signalling on an RS232 cable. The interface is

programmable over a variety of bit rates; no, even or odd parity; stop bit

and hardware flow control. The default condition on power-up is pre-

assigned in the external Flash. Two-way hardware flow control is

implemented by UART_RTS and UART_CTS. UART_RTS is an output

and is active low. UART_CTS is an input and is active low. These

signals operate according to normal industry convention.

By writing different values to the S register the UART_RI can be

continuously polled to detect incoming communication. The UART_RI

signal serves to indicate incoming calls.

UART_DSR is an active low input. It should be connected to DTR output

of the host. When the module is running in high speed mode (See

definition for S Register 512), this pin should be asserted by the host to

ensure connection is maintained. A deassertion is taken to mean that the

connection should be dropped, or an online command mode is being

requested.

The module communicates with the customer application using the

following signals:

RS-232

• Port /TXD @ application sends data to the module's UART_RX

signal line

• Port /RXD @ application receives data from the module's

UART_TX signal line

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