TP3410 datasheet(12/32 Pages) NSC

12 / 32 page

Functional Description (Continued)

TLH9151 – 12

FIGURE 5-1 Format 1

TLH9151 – 13

FIGURE 5-2 Format 2

TLH9151 – 14

FIGURE 5-3 Format 3

Shown with example of Time-slot Assignment and FSa e FSb

FIGURE 5 D-Port Interface Timing Using BCLK

70 MICROWIRE CONTROL PORT (MW e 1)

When Format 1 2 3 or 4 is used control information and

maintenance channel data is written into and read back

from the TP3410 via the Microwire port consisting of the

control clock CCLK the serial data input CI and output

CO the Chip Select input CS and the interrupt output INT

The MW pin must be tied high to enable this port and the

port may be used regardless of whether the device is pow-

ered up or down

Figures 6 and14 show the timing which is

compatible with the Microwire port on the HPC and COPs

families of microcontrollers and Tables II and III list the con-

trol functions and status indicators

All read and write operations require 2 contiguous bytes As

shown in Tables II and III the first byte is the register ad-

dress and the second byte is the data byte Status Registers

request service under control of the Interrupt Stack with the

priority order listed in Table III

To shift data to and from the TP3410 CCLK must be pulsed

high 16 times while CS is low Data on the CI input is shifted

into the serial input register on the rising edge of each CCLK

pulse simultaneously data is shifted out from CO on each

falling edge of CCLK Bit 7 of byte 1 is shifted first CS must

return high at the end of the 2nd byte after which the con-

tents of the input shift register are decoded and the data is

loaded into the appropriate programmable register Pulling

CS low also clears the INT pin if it was pulled low if another

interrupt condition is queued on the Interrupt Stack it can

only pull the INT pin low when CS is high When CS is high

the CO pin is in the high-impedance state enabling the CO

pins of many devices to be multiplexed together

TP3410 Datasheet(PDF) 12 Page - National Semiconductor (TI)