Cteni portu ISA

[Slavomir Skopalik]

To je divne, nemate tam jeste nektera jina zarizeni ?
Zkuste prosim treba SCSI adapter, nebo zvokuvku, pokud nemate video kartu.
Proste jen ctete jeji port, dale zkuste cist port nejakeho PCI zarizeni.
Predpokladam, ze vsechny testy provadite v dosu v Real modu CPU,
pokud ne, nemusi to byt primo problem vaseho programu ci vaseho zarizeni.


	Slavek
> 
> Jedna se o ISA kartu vlastni vyroby, ktera ihned po adresaci HW signalizuje
> "zadne dalsi WaitStates".
> Zkousel jsem ji nastavit na ruzne adresy (278h, 100h), ale stale z ni dokazu
> cist pouze 500kHz.
> Prolezl jsem cely SetUp, ale pro ISA se tam nenastavuje nic.
> Jirka Netopil
> 
> > -----Original Message-----
> > From: Slavomir Skopalik [mailto:skopalik@atlas.cz]
> > Sent: Thursday, November 16, 2000 12:37 PM
> > To: Multiple recipients of list
> > Subject: RE: Cteni portu ISA
> >
> >
> > Ono taky zalezi na HW, co je na te ISE, zkuste cist napriklad
> > z portu casovace (integrovane priferie),
> > potom z portu ISA video karty a pak s pararelniho portu (o
> > ten Vam asi jde).
> > jinak jsem zkousel EPP a dostal jsem se na cca 0.5 - 1 MB/sec
> > podle delky kabelu
> > a schopnostem druheho konce (zarizeni). On totiz EPP (a asi i
> > ECP) port ceka dokud
> > zarizeni nepotvrdi prijem (nebo na time out).
> >
> > Slaek
> >
> > >
> > > Nevite nekdo, proc nedokazu cist z portu na ISA smernici
> > rychleji nez 500kHz
> > > ?
> > > Stejne je to z Windows i z DOSu (nabootovano do DOSu), na
> > dvou ruznych
> > > pocitacich (Pentium 100MHz a Duron 700MHz).
> > > Podle nize uvedeneho by to melo jit rychlosti 2,7MHz (v
> > 16-bit. rezimu - ten
> > > moje karta pouziva).
> > > Nameril jsem v 16-ti bitovem rezimu asi 500kHz a v 8-mi
> > bitovem asi 330kHz.
> > > Pouzivam nasledujici rutinu a merim cas, za jaky se to provede:
> > > mov dx,PortNaISA
> > > mov bx,1000
> > > cli
> > > sm1: mov cx,10000
> > > sm2: in ax,dx
> > > loop sm2
> > > dec bx
> > > jnz sm1
> > > sti
> > > Netusite nekdo, co delam spatne ? Jak to zrychlit ?
> > > Jirka Netopil
> > >
> > > Speed:
> > > Q: How can Parallel Port ISA card support quoted rates of
> > data transfer in
> > > excess of 1MB/sec ? As far a I know every in/out command
> > for an ISA bus
> > > address takes at least 1 microsecond to perform REGARDLESS
> > of processor
> > > speed ?
> > > A: A simple parallel-port read or write does take one
> > ISA-bus cycle, and on
> > > most systems, the bus speed is around 1.3 Mhz, so one cycle
> > is a little
> > > under 1 microsecond. A complete data transfer on the
> > original parallel port
> > > usually takes at least 4 cycles, however: check the Busy
> > status, write the
> > > data, bring Strobe low, then high. On ports that support
> > EPP and ECP modes,
> > > in these modes the port hardware does the handshake, and a
> > complete transfer
> > > can take place in 1 bus cycle.
> > > There are at least two ways of getting faster data
> > transfers: Some ports
> > > support a "fast mode" that uses the ISA bus's NOWS (no wait
> > state) signal to
> > > cause the CPU to skip 3 wait states. This mode is twice as
> > fast, or around
> > > 2.7 Mhz. ECPs also include hardware support for data
> > decompressing (&
> > > sometimes compressing, though that's often left for
> > software), so the
> > > effective rate of data transmission can be much faster than
> > the number of
> > > bytes written or read per second. Also, ECPs may be able to
> > transfer data
> > > between the host's and peripheral's ECP buffers at rates
> > greater than 1 Mhz,
> > > though the buffers are typically just 8 bytes.
> > >
> >
>