IDT77V400 Integrated Device Technology, IDT77V400 Datasheet - Page 28

• Manufacturer Part Number: IDT77V400
• Description: 1.24 Gbps Switching Memory **not Recommended For New Designs**
• Manufacturer: Integrated Device Technology

, Q  6 W
, Q  6 W U U U U H D P
, Q  6 W
, Q  6 W
77V011 and for the CPU to receive information from the 77V011. Cells
are received on the DTxDATA[7:0] bus. All cells received on the
DTxDATA[7:0] data bus are filtered by the cell interpreter to determine if
they are In-Stream
Stream
value is 0x000001FX, which can be changed by writing to the In-
Stream
that matches the In-Stream
Register. All four In-Stream
one four byte write with an In-Stream
to LSB. The new cell header will be used for returning a Reply Notifica-
tion cell, following the write operation.
Discover/Identify, Reset, Register Read, Register Write, Event Notifica-
tion and Reply Notification.
and is used to either discover the 77V011 or to ensure that the 77V011 is
still attached (heart beat).
cates that the 77V011 must perform a hard reset and re-initialize itself to
its default state.
more registers. Up to 31-bytes can be read with one In-Stream
registers. Up to 31-bytes can be written with one In-Stream
and indicates that an event has happened that requires CPU interven-
tion.
in response to command cells sent by the CPU. The 77V011 will
generate a Reply Notification response to a Discover/Identify, Register
Read and Register Write command, but not for a Reset command. This
option is enabled by setting the Acknowledge Request bit in the
Message Type Field of the In-Stream™ command cell.
slightly depending on the type of command the cell caries.
programming cell address is in the first 28-bits with the default value of
GFC =0x0, VPI =0x0, VCI =0x001F, PT/CLP =0xX, where X=don't care.
The remaining byte is the HEC.
tion. This field is two bytes wide and is used to correlate messages
requiring a reply to a command. This allows more than one command to
be sent to a device without waiting for a Reply Notification cell, as the
field is copied from the Command cell to the Reply Notification cell. The
2-byte field is set to zero when an Event Notification cell is generated by
the 77V011, with the zero value being valid for this condition only. It is up
to the CPU to generate and manage values for it's In-Stream™
commands and not re-use the value for some set amount of time.
IDT77V011
In-Stream
The 77V011 supports the following set of In-Stream
The Discover/Identify command is sent by the CPU to the 77V011,
The Reset command is sent from the CPU to the 77V011, which indi-
The Register Read command is used to read the value of one or
The Register Write command is used to write a value to one or more
The Event Notification command is sent from the 77V011 to the CPU
The Reply Notification command is sent from the 77V011 to the CPU
The In-Stream™ cell format is broken up into six sections, which vary
The first five bytes contain the cell header. The In-Stream™
Bytes six and seven of the cell contain the Transaction ID informa-
™
™
Cell Header 1, 2, 3 and 4 registers, and have a subport value
programming cells have a unique cell header. The default
H D P ΠΠΠΠ3 3 3 3 U U U U R R R R J U J U J U J U D P P L Q J
H D P
H D P
™
programming cells are used to carry commands to the
™
programming cells. In order to be recolonized In-
™
™
Subport field of the Subport Configuration
Cell Header registers can be written to in
D P P L Q J
D P P L Q J
D P P L Q J
™
cell. The bytes are written MSB
™
™
cell.
functions,
™
cell.
28 of 43
command the cell contains. Bit location eight is not used. Bit seven is
the Acknowledge Request bit, which indicates if an acknowledgement to
the command cell is required or not. When a Reply Notification cell has
to be returned this bit is set to a one. When the Reply Notification cell is
returned the bit is reset to zero by the 77V011. This option is not valid
with the Reset command, which does not return a Reply Notification
cell. Bit six is the Acknowledge bit which indicates whether the cell is a
Reply Notification cell or a Command cell. This bit is set to a zero when
the cell is a Command cell, and is set to a one, by the 77V011, when the
cell is a Reply Notification cell. Bits one thorough five are the Message
Type Indicator. There are currently five commands for this field. The
Discover/Identify (value = 0x2) command, which will generate a Reply
Notification cell with 32 bytes of device specific data located in the
Message Data field. The Reset (value = 0x3) command performs a
reset on the 77V011. There is no Reply Notification cell returned for this
command. The Read Registers (value = 0x5) command performs a read
operation to a set of consecutive registers. The returned register data is
contained in the Message Data field. The Write Registers (value = 0x6)
command performs a write operation to a set of consecutive registers.
The data to be written is contained in the Message Data field. The Event
Notification (value = 0x8) command generates a Event Notification cell
indicating that an interrupt has been detected.
this field depending on the type of command the cell carries. When the
cell contains either the Register Read/Write, or Event Notification
command this field must contain a value of 0x01 in byte location 9 to be
valid. The remaining six bytes are not used and should contain zeros.
When the cell contains the Discovery/Identify command this field
contains data from the EEPROM, with data from EEPROM byte location
8 being written to the first byte position of this field.
field is dependant on the Message Type field. A Read or Write
command will have a Message Data field divided into three sub fields.
The first sub field is one byte wide and indicates how many bytes of data
are valid in the data portion of the Message Data field. The second sub
field is three bytes wide and contains the base address for the Read or
Write command. The third sub field is the valid data and padding. Valid
data is written starting at the base address in accordance with the
number of valid bytes indicator (first sub field). The remaining space, if
any, is padded with zeros. A Discover/Identify command has a Message
Data field divided into two sub fields.The first sub field is the first 25-
bytes of the Message Data field, which contains up to 25 bytes read
from the EEPROM, starting at EEPROM byte location 15. The
remaining bytes are reserved. An Event Notification command will have
a Message Data field split into two sub fields. The first sub field is two
bytes wide and contains an event number, which is always 0x0100. The
second sub field contains one byte of data (byte 18) indicating what type
of event happened, which is described in the Event Notification Table.
The remaining bytes 19 to 51 are padding and contain zeros.
byte 52 containing zeros. The CRC-10 is generated and used in the
same manner as in AAL3/4 cells.
Byte 8 contains the Message Type field, which indicates what type of
Bytes 9 thorough 15 are the Device ID field. There are two formats to
Bytes 16 thorough 51 are the Message Data field. The layout of this
Bytes 52 and 53 contain the CRC-10 trailer, with the upper six bits of
March 15, 2001