Measurement-computing CIO-DAS16 Manual do Utilizador descarregar pdf (Página 26)

D/A 1 REGISTERS

BASE ADDRESS +6

XXXXD/A12D/A11D/A10D/A9

01234567

BASE ADDRESS +7

D/A8D/A7D/A6D/A5D/A4D/A3D/A2D/A1

01234567

WRITE ONLY:

Each 12-bit D/A output line has two registers. The first contains the four least significant bits of the data and four bits

that don't matter. The second register contains the eight most significant bits of the data.

The D/A will be updated when the eight most significant bits (upper register) are written. In this way, the lower four bits

can be written with no effect on the D/A output until the remainder of the data is written to the upper eight bits.

4.6 STATUS REGISTER

BASE ADDRESS + 8

CH1CH2CH4CH8INTMUXU/BEOC

01234567

A read mostly, one-function-write register.

READ:

EOC = 1, the A/D converter is busy. EOC = 0, it is free.

U/B = 1, the amplifier is in Unipolar mode. U/B = 0, is bipolar.

MUX = 1, Channels are configured 16 single ended. MUX = 0, 8 differential.

INT = 1, an external pulse has been received. INT = 0, the flip-flop is ready to receive a pulse..

There is a flip-flop on the TRIGGER input (pin 25) which will latch a pulse as short as 200 ns. After being triggered, this

flip-flop must be reset by a write to this register. Your interrupt service routine must do this before another interrupt

trigger can be received.

CH8, CH4, CH2 and CH1 make up a binary number between 0 and 15 indicating the channel number that the MUX is

currently set to. It is valid only when EOC = 0. The channel MUX increments shortly after EOC = 1 so may be in a state

of transition when EOC = 1. The binary weight of each bit is shown in Table 4-1.

WRITE:

A write of any data to this register resets the flip-flop on the pin 25 input and sets the INT bit to 0.

1 2 ... 21 22 23 24 25 26 27 28 29 30 31 ... 35 36

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Measurement-computing CIO-DAS16 Manual do Utilizador Página 26