| 数据搜索系统,热门电子元器件搜索 |
|
ICS1893CFILF 数据表(PDF) 40 Page - Integrated Circuit Systems |
|
|
|||||||||||||||||||||||||||||
ICS1893CFILF 数据表(HTML) 40 Page - Integrated Circuit Systems |
|
40 / 126 page ![]() ICS1893CF, Rev. F, 03/01/07 Mar. 2007 40 Chapter 6 Functional Blocks ICS1893CF Data Sheet - Release Copyright © 2007, Integrated Device Technology, Inc. All rights reserved. Note: The Management Frame Structure starts from and returns to an IDLE condition. However, the IDLE periods are not part of the Management Frame Structure. 6.6.2.1 Management Frame Preamble The ICS1893CF continually monitors its serial management interface for either valid data or a Management Frame (MF) Preamble, based upon the setting of the MF Preamble Suppression bit, 1.6. When the MF Preamble Suppression is disabled, an ICS1893CF waits for a MF Preamble which indicates the start of an STA transaction. A Management Frame Preamble is a pattern of 32 contiguous logic one bits on the MDIO pin, along with 32 corresponding clock cycles on the MDC pin. The ICS1893CF supports the Management Frame (MF) Preamble Suppression capability on its Management Interface, thereby providing a method to shorten the Management Frame and provide an STA with faster access to the Management Registers. The ability to process Management Frames that do not have a preamble is provided by the Management Frame Preamble Suppression bit, (bit 1.6 in the ICS1893CF’s Status Register). This is an ISO/IEC defined status bit that is intended to provide an indication of whether or not a PHY supports the MF Preamble Suppression feature. In order to maintain backward compatibility with the ICS1890, which did not support MF Preamble Suppression, the ICS1893CF MF Preamble Suppression bit is a Command Override Write bit which defaults to a logic zero. An STA can enable MF Preamble Suppression by writing a logic one to bit 1.6 subsequent to a write of logic one to the Command Override bit, 16.15. For an explanation of the Command Override Write bits, see Section 7.1.2, “Management Register Bit Access”. 6.6.2.2 Management Frame Start A valid Management Frame includes a start-of-frame delimiter, SFD, immediately following the preamble. The SFD bit pattern is 01b and is synchronous with two clock cycles on the MDC pin. 6.6.2.3 Management Frame Operation Code A valid Management Frame includes an operation code (OP) immediately following the start-of-frame delimiter. There are two valid operation codes: one for reading from a management register, 10b, and one for writing to a management register, 01b. The ICS1893CF does not respond to the codes 00b and 11b, which the ISO/IEC specification defines as invalid. 6.6.2.4 Management Frame PHY Address The two-wire, Serial Management Interface is specified to allow busing (that is, the sharing of the two wires among multiple PHYs). The Management Frame includes a 5-bit PHY Address field, PHYAD, allowing for 32 unique addresses. An STA uniquely identifies each of the PHYs that share a single serial management interface by using this 5-bit PHY Address field, PHYAD. Table 6-1. Management Frame Structure Summary Frame Field Data Comment Acronym Frame Function PRE Preamble (Bit 1.6) 11..11 32 ones SFD Start of Frame 01 2 bits OP Operation Code 10/01 (read/write) 2 bits PHYAD PHY Address (Bits 16.10:6) AAAAA 5 bits REGAD Register Address RRRRR 5 bits TA Turnaround Z0/10 (read/write) 2 bits DATA Data DDD..DD 16 bits |
|
链接网址 |
| ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 数据表链接 | 链接交换 | 制造商名单 All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |