Calibre UK IC Communication Adapter ICA93LV User Manual - page 12

Revision 1.7

Page 11 of 27

09/12/1999

Name:

setup (baseaddr%, own%, sclk%)

Usage:

call setup(baseaddr%, own%, sclk%)

Function:

procedure to set up I

2

C Communications Adapter.

Parameters are:

baseaddr%

base address of adapter set by links on circuit board.

own%

I

2

C address to which the adapter is to respond in slave mode. This forms the

upper 7 bits of the 8 bit address, the lowest bit being the Read(1) or Write (0) bit.

This means that if own% = &h57, the card will respond to a Write to address

&hAF. Be sure not to select an address that is already in use by any other device

in your I

2

C system. If own% &h00 the adapter will monitor all I

2

C bus information

but will not affect any data transfers, thus acting as a bus monitor

sclk%

the SCL clock rate (bit rate for I

2

C serial bus).

Value of sclk%

Approximate SCL (kHz)

0

90

1

45

2

11

3

1.5

Value Returned:none.

I

2

C status on exit from routine:

The I

2

C Communications Adapter will have the serial interface enabled, also data

reception acknowledge will be enabled. The status register will contain &h81

(assuming that no other masters exist on the I

2

C system, if this is not the case

then the contents of the status register will also depend on externally generated

bus activity).

Example Usage:

(see also sample programs)

$include “i2c.inc”

‘* This contains the I

2

C routines*

baseaddr% = &h310

‘* Adapter’s base address = &h310 (hex) *

own% = &h57

‘* Own slave address set to &h57 (hex) *

sclk% = 1

‘* Serial clock rate set to 45KHz *

call setup(baseaddr%, own%, sclk%)

print”I

2

C Communications Adapter initialised”

‘* This will set up the I

2

C Communications Adapter with a base address *

‘* of &h310, an I

2

C slave address of &hAE and a SCL clock rate of *

‘* approximately 45KHz *

5.2.2.

I

2

C Status Checking Routine

Name:

FNgetstatus%(Controladdress%)

Usage:

status% = FNgetstatus%(controladdress%)

Function:

function to read status register of I

2

C Communications Adapter.

Parameters are:

controladdress%

address of I

2

C control register. This is equal to 1+(base address of adapter set

by links on circuit board).

Value Returned:

where status is an integer from &h00 to &hFF which indicates the current status

of the I

2

C communications Adapter. Appendix A for details of the status values

returned.

I

2

C status on exit from routine:

The status of the I

2

C Communications Adapter will not be affected by using the

FNgetstatus% function.

Example Usage:

(see also sample programs)

$include “i2c.inc”

‘* This contains the I

2

C routines *