ST70135 datasheet(22/29 Pages) STMICROELECTRONICS

22 / 29 page

ST70135A

22/29

The implementation must guarantee that all active

SLR_Valid signals must be separated by at least 8

clock cycles. Refer to Figure 20. The SLR_FRAME

signals are asserted when the first pair of bits of a

frame are transferred. For the fast channel a frame

is defined as a superframe timebase.

For the interleaved channel the frame is defined

by a timebase period of 4 superframes. Both

timebases are synchronized to the data flow.

Transmit SLAP Interface

The Transmit interface uses the following signals

(refer to Figure 21):

– SLT_REQ: byte request.

– SLT_FRAME: start of frame indication.

– SLT_DATA [1:0] data pins, a byte is transferred

2 bits at the time in 4 successive clock cycles.

MSB first, odd bits on SLT_DATA [1].

The logical timing diagram is shown in Figure 22.

The delay between Request and the associated

data byte is defined as 8 cycles.

The SLT_FRAME signals are asserted when the

first pair of bits of a frame are transferred. For the

fast channel a frame is defined as a superframe

timebase.

For the interleaved channel the frame is defined

by a timebase period of 4 superframes.

Both timebases are synchronized to the data flow

and guarantee that the frame indication is

asserted when the first bits of the first DMT

symbol are transferred.

SLAP INTERFACE, AC Electrical Characteristics

Figure 21 : Interface Towards PHY Layer

Figure 22 : Interface Timing

EXTERNAL

CLOCK

COMPONENT

(SLAVE)

MODEM

(MASTER)

REQUEST

2 DATA

FRAME

Tper

Thd

CLOCK

ALL INPUTS

ALL OUTPUTS

Figure 23 : Transmit SLAP Interface Timing Diagram

Symbol

Parameter

Test Conditi on

Minimum

Typical

Maximum

Unit

Tper

Clock Period

Refer to MCLK

Clock High

Clock Low

Setup

Thd

Hold

Data Delay

20pF load

One byte in 4 cycles

CLOCK

Undefined

Request may be repeated

SLT_DATA(0)

SLT_FRAME

after 4 cycles

Delay Request-data equals 8 cycles

Repeated each superframe/

S-frame

STM_CLOCK

SLT_DATA(1)

SLT_REQUEST

ST70135 Folha de dados(PDF) 22 Page - STMicroelectronics

ST70135 Folha de dados(HTML) 22 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

Folha de dados Download

Ligação URL