參數資料
型號: 37C67X
廠商: SMSC Corporation
英文描述: ENHANCED SUPER I/O CONTROLLER WITH FAST IR
中文描述: 增強的超級I / O控制器,快速紅外線
文件頁數: 156/194頁
文件大小: 546K
代理商: 37C67X
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁第117頁第118頁第119頁第120頁第121頁第122頁第123頁第124頁第125頁第126頁第127頁第128頁第129頁第130頁第131頁第132頁第133頁第134頁第135頁第136頁第137頁第138頁第139頁第140頁第141頁第142頁第143頁第144頁第145頁第146頁第147頁第148頁第149頁第150頁第151頁第152頁第153頁第154頁第155頁當前第156頁第157頁第158頁第159頁第160頁第161頁第162頁第163頁第164頁第165頁第166頁第167頁第168頁第169頁第170頁第171頁第172頁第173頁第174頁第175頁第176頁第177頁第178頁第179頁第180頁第181頁第182頁第183頁第184頁第185頁第186頁第187頁第188頁第189頁第190頁第191頁第192頁第193頁第194頁
64
with a single Relative Seek command is 255
(D).
The internal register, PCN, will overflow as the
cylinder number crosses track 255 and will
contain 39 (D). The resulting PCN value is thus
(RCN + PCN) mod 256. Functionally, the FDC
starts counting from 0 again as the track
number goes above 255 (D).
It is the user's
responsibility to compensate FDC functions
(precompensation
track
number)
when
accessing tracks greater than 255. The FDC
does not keep track that it is working in an
"extended track area" (greater than 255). Any
command issued will use the current PCN value
except for the Recalibrate command, which only
looks for the TRACK0 signal.
Recalibrate will
return an error if the head is farther than 79 due
to its limitation of issuing a maximum of 80 step
pulses. The user simply needs to issue a second
Recalibrate command. The Seek command and
implied seeks will function correctly within the
44 (D) track (299-255) area of the "extended
track area". It is the user's responsibility not to
issue a new track position that will exceed the
maximum track that is present in the extended
area.
To return to the standard floppy range (0-255) of
tracks, a Relative Seek should be issued to
cross the track 255 boundary.
A Relative Seek can be used instead of the
normal Seek, but the host is required to
calculate the difference between the current
head
location
and
the
new
(target)
head
location. This may require the host to issue a
Read ID command to ensure that the head is
physically on the track that software assumes it
to be.
Different FDC commands will return
different cylinder results which may be difficult
to keep track of with software without the Read
ID command.
Perpendicular Mode
The Perpendicular Mode command should be
issued prior to executing Read/Write/Format
commands that access a disk drive with
perpendicular recording capability.
With this
command, the length of the Gap2 field and VCO
enable timing can be altered to accommodate
the unique requirements of these drives. Table
30 describes the effects of the WGATE and
GAP bits for the Perpendicular Mode command.
Upon a reset, the FDC will default to the
conventional mode (WGATE = 0, GAP = 0).
Selection
of
the
500
Kbps
and
1
Mbps
perpendicular modes is independent of the
actual data rate selected in the Data Rate Select
Register. The user must ensure that these two
data rates remain consistent.
The Gap2 and VCO timing requirements for
perpendicular recording type drives are dictated
by the design of the read/write head.
In the
design of this head, a pre-erase head precedes
the normal read/write head by a distance of 200
micrometers. This works out to about 38 bytes
at a 1 Mbps recording density. Whenever the
write head is enabled by the Write Gate signal,
the pre-erase head is also activated at the same
time. Thus, when the write head is initially
turned on, flux transitions recorded on the media
for the first 38 bytes will not be preconditioned
with the pre-erase head since it has not yet been
activated. To accommodate this head activation
and
deactivation
time,
the
Gap2
field
is
expanded to a length of 41 bytes. The format
field shown on Page 57 illustrates the change in
the Gap2 field size for the perpendicular format.
相關PDF資料
PDF描述
37C957FR ULTRA I/O CONTROLLER FOR PORTABLE APPLICATIONS
37FMA1-ABW31N SPECIAL SWITCH-PIEZO SWITCH, SPST, MOMENTARY, 0.2A, 24VDC, PANEL MOUNT-THREADED
37FML1-BEW31N SPECIAL SWITCH-PIEZO SWITCH, SPST, MOMENTARY, 0.2A, 24VDC, PANEL MOUNT-THREADED
37FML2-ACW21N SPECIAL SWITCH-PIEZO SWITCH, SPST, MOMENTARY, 1A, 24VDC, PANEL MOUNT-THREADED
37FMA1-AAW11N SPECIAL SWITCH-PIEZO SWITCH, SPST, MOMENTARY, 0.2A, 24VDC, PANEL MOUNT-THREADED
相關代理商/技術參數
參數描述
37C-6BH-5-5 制造商:Birtcher Products 功能描述:
37C72U-185 制造商:White-Rodgers 功能描述:
37C73U-170 制造商:White-Rodgers 功能描述:
37C73U-171 制造商:White-Rodgers 功能描述:
37C922BQFP 制造商:SMSC 功能描述: