beautypg.com

Operation in asynchronous mode (op. modes 0 and 1) – FUJITSU F2MCTM-16LX User Manual

Page 438

background image

422

CHAPTER 20 LIN-UART

20.7.1

Operation in Asynchronous Mode (Op. Modes 0 and 1)

When LIN-UART is used in operation mode 0 (normal mode) or operation mode 1
(multiprocessor mode), the asynchronous transfer mode is selected.

Operation in Asynchronous Mode

Transfer data format

Generally each data transfer in the asynchronous mode operation begins with the start bit (low-level) and

ends with at least one stop bit (high-level). The direction of the bit stream (LSB first or MSB first) is

determined by the BDS bit of the Serial Status Register (SSR). The parity bit (if enabled) is always placed

between the last data bit and the (first) stop bit.

In operation mode 0 the length of the data frame can be 7 or 8 bits, with or without parity, and 1 or 2 stop

bits.

In operation mode 1 the length of the data frame can be 7 or 8 bits with a following address-/data-selection

bit instead of a parity bit. 1 or 2 stop bits can be selected.

The calculation formula for the bit length of a transfer frame is:

Length = 1 + d + p + s

(d = number of data bits [7 or 8], p = parity [0 or 1], s = number of stop bits [1 or 2]

Figure 20.7-1 shows the data format in the asynchronous mode.