PDI1394P11 データシートの表示（PDF） - Philips Electronics
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PDI1394P11 Datasheet PDF : 20 Pages
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Philips Semiconductors
3-port physical layer interface
Product specification
PDI1394P11
18.18 Isolation Barrier disable (ISO–, pin 62)
When ISO– is high, busholder circuits are enabled on the LREQ,
PD, and LPS input pins and on the CTL, and Data bidirectional pins.
This mode also allows isolation using a single 1nF capacitor per
signal line. When ISO– is low, busholder circuits are disabled and
isolation can be realized by using the scheme explained in Annex J
of the 1394–1995 spec.
18.19 Supply filters (AVDD, pins [24, 25, 51, 55],
DVDD, pins [5,6,19,20], and PLLVDD, pin 58)
A combination of decoupling capacitors is suggested for each
supply group, such as paralleled 10 µF and 0.1 µF. The high
frequency 0.1 µF capacitors should be mounted as close as
possible to the PDI1394P11 device supply leads. These supply lines
are separated on the IC to provide noise isolation. They should be
tied together at a low impedance point on the circuit board.
Individual filter networks are desirable.
Details of a phy-link Interface supporting an optional isolation barrier
are provided in Annex J of the 1394 standard.
19.0 PRINCIPLES OF OPERATION
The PDI1394P11 is designed to operate with a link layer controller.
These devices use an interface such as described in Annex J of the
1394 standard. The following describes the operation of the phy-link
interface.
19.1 Data Transfer and Clock rates
The PDI1394P11 supports 100/200 Mbit/s data transfer, and has
four bi-directional data lines D[0:3] crossing the interface. In 100
Mbit/s operation only D[0:1] pins are used, in 200 Mbit/s operations
all D[0:3] pins are used for data transfer. The unused D[n] pins are
driven low. In addition there are two bi-directional control lines CTL[0:1],
the 50 MHz SYSCLK line from the phy to the link, and the link request
line LREQ from the link to the phy. The PDI1394P11 has control of
all the bi-directional pins. The link is allowed to drive these pins only
after it has been given permission by the phy. The dedicated LREQ
request pin is used by the link for any activity which it wishes to
initiate.
When the phy has control of the bus the CTL[0:1] lines are encoded
as follows:
CTL [0:1] NAME DESCRIPTION OF ACTIVITY
00
Idle
No activity is occurring (this is the default
mode).
01
Status Status information is being sent from the
phy to the link.
10
Receive An incoming packet is being sent from the
phy to the link.
11
Grant The link has been given control of the bus
to send an outgoing packet.
When the link has control of the bus (phy permission) the CTL[0:1]
lines are encoded as follows:
CTL [0:1] NAME DESCRIPTION OF ACTIVITY
00
Idle
The link releases the bus (transmission
has been completed).
01
Hold
The link is holding the bus while data is
being prepared for transmission or
sending another packet without arbitrating.
10
Transmit An outgoing packet is being sent from the
link to the phy.
11
NA
None
19.2 Request
When the link layer controller wishes to request the bus, or access a
register that is located in the PDI1394P11, a serial stream of
information is sent across the LREQ line. The length of the stream
will vary depending on whether the transfer is a bus request, a read
command, or a write command. Regardless of the type of transfer, a
start bit of 1 is required at the beginning of the stream, and a stop bit
of 0 is required at the end of the stream. Bit 0 is the most significant,
and is transmitted first. The LREQ line will be required to idle low
(logic level 0).
19.2.1 Link Layer Controller Bus Request
For a Bus Request, the length of the LREQ data stream is 7 bits as
follows:
BIT(S) NAME
DESCRIPTION
0
Start Bit
Indicates the beginning of the transfer
(always 1)
1–3 Request Type Indicates the type of bus request (see
the table below for the encoding of this
field)
4–5 Request Speed This should be 00 for PDI1394P11’s
100 Mbit/s speed and 01 for
200 Mbit/s speed.
6
Stop Bit
Indicates the end of the transfer
(always 0)
19.2.2 Link Layer Controller Requests Read Register Access
For a Read Register Request, the length of the LREQ data stream is
9 bits as follows:
BIT(S) NAME
DESCRIPTION
0
Start Bit
Indicates the beginning of the transfer
(always 1)
1–3 Request Type Always a 100 indicating that this is a
read register request
4–7 Address
The address of the phy register to be read
8
Stop Bit
Indicates the end of the transfer (always 0)
19.2.3 Link Layer Controller Requests Write Register Access
For a Write Register Request, the length of the LREQ data stream is
17 bits. The details of bits are as shown below:
BIT(S) NAME
DESCRIPTION
0
Start Bit
Indicates the beginning of the transfer
(always 1)
1–3 Request Type Always a 101 indicating that this is a
write register request
4–7 Address
The address of the phy register to be
written to
8–15 Data
The data that is to be written to the
specified register address
16
Stop Bit
Indicates the end of the transfer (always 0)
1999 Apr 09
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