TP3465V datasheet(8/17 Pages) NSC

8 / 17 page

Software Driver Procedures (Continued)

4 Write to SKR to set the div bits to support the fastest SK

clock rate supported by the peripherals Set inten e 1 if

the uwdone status is to set an INTerrupt to the host

processor (available only in the Non-multiplexed bus im-

plementation of TP3465 28-pin package) The ms and

the soi bit are set to 0 upon power up and indicate that

the MID is in MICROWIRE Master mode with SO as an

output pin as normal

SENDING DATA TO PERIPHERALS (Normal Mode)

Assume sending 16-bit data to a MICROWIRE based device

connected to any one of CS0 to CS7

1 Write to CS (Chip Select) register and reset the appropri-

ate bit and thus activate the corresponding CS pin

2 Write LOW byte data to SMB (Second MICROWIRE Byte)

WIRE Byte) register

3 Read the ST (Status) register and stay in a loop until

uwdone

bit is set

4 Write to CS register and set the bit to deactivate the ap-

propriate chip select pin

SENDING DATA TO PERIPHERALS

(Hardware Assisted Chip Select)

Assuming sending 16-bit data to dev3 connected to CS3

1 Write LOW byte data to address SMB and then HIGH

byte data to FMBD3

2 Read the ST register and stay in a loop until uwdone bit

is set

Communicating with an NSC

TP3071 COMBO II Type Device

The NSC TP3071 COMBO II device has a modified MICRO-

WIRE port It shares a single pin (called COCI) for incoming

and outgoing data The MID’s SO pin may be tied to this pin

as shown in

Figure 3 and the following steps are followed

to Read from and Write to this device Assume that the chip

select for TP3071 is connected to CS1 pin

TP3071 Write Operation

a Initialization states skp1 e 1 mwm1 e 1 and soi e 0

b Data transfer options

i Set cs1 bit to 0 write LOW byte to SMB and HIGH

byte to FMB and then set cs1 bit to 1 after uwdone bit

is set to 1

ii Write LOW byte to SMB and HIGH byte to FMBD1

TP3071 Read Operation

a Initialization states skp1 e 1 mwm1 e 0 and soi e 0

b Data transfer options

i Set cs1 bit to 0 write HIGH byte to FMB wait until

uwdone

bit is set to 1 by hardware Set soi bit to 1

Write dummy LOW byte (eg 00h) to FMB wait until

uwdone

bit is set to 1 by hardware Read STATUS

from FMB address Set soi to 0 and cs1 to 1

ii Write HIGH byte to FMBD1 wait until uwdone bit is set

to 1 by hardware Set soi bit to 1 Write a dummy LOW

byte (eg 00h) to FMBD1 and wait until uwdone bit is

set to 1 by hardware Read STATUS from FMBD1 ad-

dress Set soi bit to 0

Applications

The versatile TP3465 MICROWIRE Interface Device can be

used in a number of applications involving MICROWIRE pe-

ripheral devices that need to be controlled using a standard

microprocessor which only has a parallel bus structure

ISDN TERMINAL ADAPTER

The MID can be used in ISDN terminal adapters (see

Figure

4 ) interfacing to ISDN components such as TP3420 SID as

well as non-ISDN components such as LCD display drivers

(eg COP470) and serial EEPROMs (COP494) In this ap-

plication the MID signals SK SO and SI are bussed to all

peripheral devices.

The device chip selects control lines

a total of 8 in the 28-pin package are individually connected

to each of the devices Status Interrupt from the peripherals

such as SID are connected directly to the main processor

ANALOG OR DIGITAL LINECARDS

The MID can also be used in analog and digital (ISDN and

Non-ISDN) linecard applications (see

Figure 5 ) Up to 8

MICROWIRE peripheral devices (TP3070 COMBO II or

TP3420 SIDs TP3410 UIDs or TP3401 DASLs) can be con-

nected to one MID device The Interrupts from the trans-

ceivers may be wire-ORed and fed into one interrupt line of

the main processor in which case all the devices will need

to be polled after an interrupt The efficient interface be-

tween the MID and microprocessor allows this process to

be accomplished with minimum overhead

In a given application if any of the chip select pins are not

used to perform chip select for peripherals then it may be

used as a general purpose inputoutput pin under software

control

MID SUPPORTING MASTER AND SLAVE

MICROWIRE OPERATION

The MICROWIRE serial data bus is often used as a means

of inter-processor communication The MID may be used

either as the Master of the MICROWIRE clock SK or as a

Slave to the SK clock fed via CKIN pin

Figure 6 shows an

application in which two general microprocessors communi-

cate with each other over the MICROWIRE bus At the

same time other peripherals are also connected to the serial

bus External handshaking between the two processors is

required before the MICROWIRE Byte data transfer is exe-

cuted by the master of the MICROWIRE bus

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