1893Y-10 IDT, Integrated Device Technology Inc, 1893Y-10 Datasheet - Page 58

• Manufacturer Part Number: 1893Y-10
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of 1893Y-10

• Lead Free Status / RoHS Status: Not Compliant

7.6.2.7
7.6.2.8
7.6.2.9
ICS1893 Rev C 6/6/00
A valid management frame includes a turn-around field (TA), which is a 2-bit time space between the
REGAD field and the Data field. This time allows an ICS1893 and an STA to avoid contentions during read
transactions. During an operation that is a:
•
•
A valid management frame includes a 16-bit Data field for exchanging the register contents between the
ICS1893 and the STA. All Management Registers are 16 bits wide, matching the width of the Data field.
During a transaction that is a:
•
•
If the STA attempts to:
•
•
Note:
The MDIO signal is in an idle state during the time between STA transactions. When the Serial
Management Interface is in the idle state, the ICS1893 disables (that is, tri-states) its MDIO pin, which
enters a high-impedance state. The ISO/IEC 8802-3 standard requires that an MDIO signal be idle for at
least one bit time between management transactions. However, the ICS1893 does not have this limitation
and can support a continual bit stream on its MDIO signals.
Management Frame Turnaround
Management Frame Data
Serial Management Interface Idle State
Read, an ICS1893 remains in the high-impedance state during the first bit time and subsequently drives
its MDIO pin to logic zero for the second bit time.
Write, an ICS1893 waits while the STA transmits a logic one, followed by a logic zero on its MDIO pin.
Read, (OP is 10b) the ICS1893 obtains the contents of the register identified in the REGAD field and
returns this Data to the STA synchronously with its MDC signal.
Write, (OP is 01b) the ICS1893 stores the value of the Data field in the register identified in the REGAD
field.
Read from a non-existent ICS1893 register, the ICS1893 returns logic one for all bits in the Data field,
FFFFh.
Write to a non-existent ICS1893 register, the ICS1893 isolates the Data field of the management frame
from every reaching the registers.
ICS1893 Data Sheet - Release
The first Data bit transmitted and received is the most-significant bit of a Management Register, bit
X.15.
Copyright © 2000, Integrated Circuit Systems, Inc.
All rights reserved.
58
Chapter 7 Functional Blocks
June, 2000