HPC167064 datasheet(22/34 Pages) NSC

22 / 34 page

MICROWIREPLUS Application

Figure 25 illustrates a MICROWIREPLUS arrangement for

an automotive application The microcontroller-based sys-

tem could be used to interface to an instrument cluster and

various parts of the automobile The diagram shows two

HPC167064

microcontrollers

interconnected

other

MICROWIRE peripherals HPC167064 1 is set up as the

master and initiates all data transfers HPC167064 2 is set

up as a slave answering to the master

The master microcontroller interfaces the operator with the

system and could also manage the instrument cluster in an

automotive application Information is visually presented to

the operator by means of a LCD display controlled by the

COP472 display driver The data to be displayed is sent

serially to the COP472 over the MICROWIREPLUS link

Data such as accumulated mileage could be stored and re-

trieved from the EEPROM COP494 The slave HPC167064

could be used as a fuel injection processor and generate

timing signals required to operate the fuel valves The mas-

ter processor could be used to periodically send updated

values to the slave via the MICROWIREPLUS link To

speed up the response chip select logic is implemented by

connecting an output from the master to the external inter-

rupt input on the slave

TLDD11046 – 32

FIGURE 24 MICROWIREPLUS

TLDD11046 – 33

FIGURE 25 MICROWIREPLUS Application

HPC167064 Datasheet(PDF) 22 Page - National Semiconductor (TI)