SERCON410B datasheet(29/34 Pages) STMICROELECTRONICS

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DATA STRUCTURES WITHIN THE RAM (Continued)

4.2.2 Data Containers

A data container comprises one or two 16-bit con-

trol words as well as a variable number of data

words. If the data is stored in the internal RAM

(DMA = 0) and a single buffer is used (DBUF = 0),

the data container has one buffer. Using RAM

Index

Bit

Name

Function

0-9

LEN

Number of 16-bit data words of the data block.

SVFL

Flag, whether data block uses service container (SVFL = 1).

11-13

NSV

Number of service container, which is used (0 - 7).

SCMASTER

Processing of service container in slave mode (SCMASTER = 0)

or master mode (SCMASTER = 1).

LASTDC

Last data container of the telegram (1) or further data containers

follow (0).

0-15

POS

Position of the data block within the telegram in number of words.

The first data record of a telegram has POS = 0 (only in case of

receive telegrams).

Figure 13. Structure of Data Containers

storage and double buffering (DBUF = 1), two data

buffers are needed. In case of DMA transfer (DMA

= 1) the data container only comprises the control

words (Fig. 13). The structure of the two control

words depends on whether a telegram is transmit-

ted or received:

SERCON410B

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