Omega Engineering IOP-241 用户手册

The program registers of the IOP-241 occupy eight adjacent bytes of I/O address space.  These
registers must be programmed to control the operation of the IOP-241.  The table below lists
the program registers along with their offsets relative to the I/O space base address at which
the IOP-241 is located:

Interrupt Acknowledge Register

W

7

Interrupt Status Register

R

7

Interrupt Mode Control Register

R/W

6

Port C Interrupt Enable Register

R/W

5

Data Port C Control Register

R/W

2

Data Port B Control Register

R/W

1

Data Port A Control Register

R/W

0

Table 5-1.  IOP-241 Program Registers

Each register of the IOP-241 is discussed in detail in the following sections.

The Data Port A Control Register contains the control bits for I/O channels DATA0 - DATA7.
Each I/O channel may be individually programmed for input by writing a '1' to the
appropriate bit of this register.  

General Purpose I/O bit 0

DATA0

0

General Purpose I/O bit 1

DATA1

1

General Purpose I/O bit 2

DATA2

2

General Purpose I/O bit 3

DATA3

3

General Purpose I/O bit 4

DATA4

4

General Purpose I/O bit 5

DATA5

5

General Purpose I/O bit 6

DATA6

6

General Purpose I/O bit 7

DATA7

7

Table 5-2.  Data Port A Control Register

 IOP-241 Users Manual                                                                                                                       25