THS1206

SLAS217H – MAY 1999 – REVISED JULY 2003#

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FIFO DESCRIPTION

In order to facilitate an efficient connection to today’s processors, the THS1206 is supplied with a FIFO. This integrated

FIFO enables a problem-free processing of data with today’s processors. The FIFO is provided as a flexible circular buffer.

The circular buffer integrated in the THS1206 can store up to 16 conversion values. Therefore, the amount of interrupts

to be served by a processor can be reduced significantly.

8

9

10

11

12

13

14

15

16

1

2

3

4

5

6

7

Read Pointer

Trigger Pointer

Write Pointer

Data in FIFO

Free

Figure 29. Circular Buffer

The converted data of the THS1206 is automatically written into the FIFO. To control the writing and reading process, a

write pointer, a read pointer and a trigger pointer are used. The read pointer always shows the location which is read next.

The write pointer indicates the location which contains the last written sample. With a selection of multiple analog input

channels, the converted values are written in a predefined sequence to the circular buffer (autoscan mode). In this way,

the channel information for the reading processor is continually maintained.

The FIFO can be programmed through the control register of the ADC. The user has the ability to select a specific trigger

level according to Table 13 in order to choose the configuration which best fits the application. The FIFO provides the signal

DATA_AV, which signals the processor to read the amount of data equal to the trigger level selected in Table 13. The signal

DATA_AV becomes active when the trigger condition is satisfied. The trigger condition is satisfied when as many values

as selected for the trigger level are written into the FIFO.

The signal DATA_AV could be connected to an interrupt input of a processor. In every interrupt service routine call, the

processor must read the amount of data equal to the trigger level from the ADC. The first data represents the first channel

according to the autoscan mode, which is shown in Table 10. The channel information is therefore always maintained.