Measurement-computing CIO-DAS08-AOH Bedienungsanleitung PDF herunterladen (Seite 22)

The 82C55 may be programmed to operate in Input/ Output (mode 0), Strobed Input/ Output (mode 1) or Bi-directional Bus

(mode 2).

NOTE

Information on programming the 82C55 in mode 0 is included here. Those wishing to use the 82C55 in modes 1 or 2 must

procure a data book from Intel Corporation Literature Department.

When the PC is powered up or RESET, the 82C55 is reset. This places all 24 lines in Input mode. No further programming is

needed to use the 24 lines as TTL inputs.

To program the 82C55 for other modes, the following control code byte must be assembled into on 8-bit byte.

MS = Mode Set. 1 = mode set active

Output0000

Input1111

INDEPENDENT FUNCTIONCHCLBA

Bi-Directional BusMode 2X1

Strobed Input / OutputMode 110

Input / OutputMode 000

GROUP A FUNCTIONM2M3

M1 = 0 is mode 0 for group B. Input / Output

M1 = 1 is mode 1 for group B. Strobed Input / Output

Port A, Port B, Port C-High, and Port C-Low can be independently programmed for inputs or outputs.

The two groups of ports, group A and group B, may be independently programmed in one of several modes. The most

commonly used mode is mode 0, input/output mode. The codes for programming the 82C55 in mode 0 are shown in the table

below.

D7 is always 1 and D6, D5 & D2 are always 0.

ININININ1559B1111

OUTINININ1549A0111

INOUTININ153991011

OUTOUTININ152980011

ININOUTIN147931101

OUTINOUTIN146920101

INOUTOUTIN145911001

OUTOUTOUTIN144900001

INININOUT1398B1110

OUTININOUT1388A0110

INOUTINOUT137891010

OUTOUTINOUT136880010

ININOUTOUT131831100

OUTINOUTOUT130820100

INOUTOUTOUT129811000

OUTOUTOUTOUT128800000

CLBCUADECHEXD0D1D3D4

1 2 ... 17 18 19 20 21 22 23 24 25 26 27 ... 31 32

Keine Kommentare

Measurement-computing CIO-DAS08-AOH Bedienungsanleitung Seite 22