 |
数据搜索系统，热门电子元器件搜索 |
|
|
数据搜索系统，热门电子元器件搜索 |
|
CS5530 数据表(PDF) 59 Page - National Semiconductor (TI) |
|
|
|
|||||||||||||||||||||||||||||
CS5530 数据表(HTML) 59 Page - National Semiconductor (TI) |
|
|
59 / 241 page  Revision 4.1 59 www.national.com Functional Description (Continued) 3.4.2.3 Save-To-Disk Save-to-Disk is supported by the CS5530. In this state, the power is typically removed from the CS5530, causing the state of the legacy peripheral devices to be lost. Shadow registers are provided for the devices which allows their state to be saved prior to removing power. This is necessary because the legacy AT peripheral devices used several write only registers. In order to restore the exact state of these devices on resume, the write only register values are “shadowed” so that the val- ues can be saved by the Power Management Software. The PC/AT compatible floppy port is not part of the CS5530. However, it is expected that one will be attached on the ISA bus in a SuperI/O or by some other means. Some of the FDC registers are shadowed because they cannot be safely read. They are shown in Table 3-15. Additional shadow registers for other functions are described in: • Table 3-39 "DMA Shadow Register" on page 93 • Table 3-41 "PIT Shadow Register" on page 95 • Table 3-44 "PIC Shadow Register" on page 97 • Table 3-52 "Real-Time Clock Registers" on page 104 Table 3-15. Power Management Shadow Registers Bit Description F0 Index B4h Floppy Port 3F2h Shadow Register (RO) Reset Value = 00h 7:0 Floppy Port 3F2h Shadow (Read Only): Last written value of I/O Port 3F2h. Required for support of FDC power ON/OFF and Zero Volt Suspend/Resume coherency. This register is a copy of an I/O register which cannot safely be directly read. Value in register is not deterministic of when the register is being read. It is provided here to assist in a Save-to-Disk operation. F0 Index B5h Floppy Port 3F7h Shadow Register (RO) Reset Value = 00h 7:0 Floppy Port 3F7h Shadow (Read Only): Last written value of I/O Port 3F7h. Required for support of FDC power ON/OFF and Zero Volt Suspend/Resume coherency. This register is a copy of an I/O register which cannot safely be directly read. Value in register is not deterministic of when the register is being read. It is provided here to assist in a Save-to-Disk operation. F0 Index B6h Floppy Port 1F2h Shadow Register (RO) Reset Value = 00h 7:0 Floppy Port 1F2h Shadow (Read Only): Last written value of I/O Port 1F2h. Required for support of FDC power ON/OFF and Zero Volt Suspend/Resume coherency. This register is a copy of an I/O register which cannot safely be directly read. Value in register is not deterministic of when the register is being read. It is provided here to assist in a Save-to-Disk operation. F0 Index B7h Floppy Port 1F7h Shadow Register (RO) Reset Value = 00h 7:0 Floppy Port 1F7h Shadow (Read Only): Last written value of I/O Port 1F7h. Required for support of FDC power ON/OFF and Zero Volt Suspend/Resume coherency. This register is a copy of an I/O register which cannot safely be directly read. Value in register is not deterministic of when the register is being read. It is provided here to assist in a Save-to-Disk operation. |
|
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 |
Chinese ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
