ICP DAS USA I-7188XA, Руководство пользователя

Страница: 73 / 166

I-7188XA Series User’s Manual ( Ver1.2, Feb/2014, 7MH-019-10 ) ---
73
4.12 Using the I/O Expansion Bus
As there are many serial interface devices available today, the I/O
expansion bus includes both serial and parallel interfaces. The parallel
interface is very similar to an ISA bus, so the old ISA bus design can be
migrated to the I/O expansion bus with a minimum amount of alteration.
The I/O pins of the serial bus are programmable and can be
programmed as either D/I or D/O.
The features of these serial devices are as follows:

Smaller size compared to parallel devices

Lower cost compared to parallel devices

Easier to design for isolated applications
The serial interface of the I/O expansion bus makes connecting to these
serial devices very easy.
4.12.1 Definition of an I/O Expansion Bus
The I/O expansion bus of the I-7188XA(D) module can be divided into 3
groups as follows:
1. Power supply and reset signals: VCC, GND, RESET and /RESET
2. Parallel Bus:

System clock: CLOCKA

Asynchronous ready control: ARDY

Address bus: A0 ~ A7

Data bus: D0 ~ D7

Interrupt control: INT0, INT1 and INT4

Chip select and read/write strobe: /CS, /WR and /RD
3. Serial Bus: TO_0, TO_1, TI_0, TI_1, SCLK, DIO9, DIO4 and DIO14