 |
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 |
|
PC87413 数据表(PDF) 26 Page - National Semiconductor (TI) |
|
|
|
|||||||||||||||||||||||||||||
PC87413 数据表(HTML) 26 Page - National Semiconductor (TI) |
|
|
26 / 257 page  1.0 Signal/Pin Connection and Description (Continued) www.national.com 26 Revision1.2 1.4.6 Floppy Disk Controller (FDC) Signal Pin(s) I/O Buffer Type Power Well Description DENSEL 74 O O2/12 VDD Density Select. Indicates that a high FDC density data rate (500 Kbps, 1 Mbps or 2 Mbps) or a low density data rate (250 or 300 Kbps) is selected. DIR 65 O OD12, O2/12 VDD Direction. Determines the direction of the Floppy Disk Drive (FDD) head movement (active = step in; inactive = step out) during a seek operation. DR1 DR0 70 67 O OD12,O2/12 VDD Drive Select. Decoded output signals in Two-Drive mode or encoded signals in Four-Drive mode. Controlled by bits 1 and 0 of the Digital Output Register (DOR). DRATE0 73 O O3/6 VDD Data Rate. Reflects the value of bit 0 of the Configuration Control Register (CCR) or the Data Rate Select Register (DSR), whichever was written to last. DSKCHG 57 I INT VDD Disk Change. Indicates if the drive door has been opened. HDSEL 58 O OD12,O2/12 VDD Head Select. Determines which side of the FDD is accessed. Active low selects side 1; inactive selects side 0. INDEX 72 I INT VDD Index. Indicates the beginning of an FDD track. MSEN0 45 I INT VDD Automatic Media Sense. Identifies the media type of the floppy disk in drives 1 and 0 (if the drives support this protocol). MTR1 MTR0 66 71 O OD12,O2/12 VDD Motor Select. Active low, motor enable lines for drives 1 and 0, controlled by bits D7-4 of the Digital Output Register (DOR). MTR0 is used to decode DR1 and DR0 in Four-Drive mode. RDATA59 I INT VDD Read Data. Raw serial input data stream read from the FDD. STEP 64 O OD12,O2/12 VDD Step. Issues pulses to the disk drive at a software programmable rate to move the head during a seek operation. TRK0 61 I INT VDD Track 0. Indicates to the controller that the head of the selected floppy disk drive is at track 0. WDATA63 O OD12,O2/12 VDD Write Data. Carries out the pre-compensated serial data that is written to the FDD. Pre-compensation is software selectable. WGATE 62 O OD12,O2/12 VDD Write Gate. Enables the write circuitry of the selected FDD. WGATE is designed to prevent glitches during power-up and power-down. This prevents writing to the disk when power is cycled. WP 60 I INT VDD Write Protected. Indicates that the disk in the selected drive is write protected. |
|
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
