DIGITAL-LOGIC SM800/900DK, Technical User'S Manual

Page: 82 / 103

DIGITAL-LOGIC AG
SM800/900DK Technical Manual V1.2B
82
13.7.3. IDE Interface
The LX800/900 supports only one IDE port, assigned as the primary IDE port.
The IDE signals are 3.3V output and 5Volt tolerant inputs in the CD5536.
470 Ω pull-down resistors on Pin28 of the IDE connector (ALE). Support cable select (ALE) is a PC97
requirement. The state of the cable select pin determines the master/slave configuration of the hard
drive at the end of the cable.
The primary IDE connector uses IRQ14.
The ATA-4 specification requires 33 Ω series terminating resistors on DIOR, DIOW#, DCS[1,3]#,
DA[2:0], DDACK# and DD[15:0]. These series termination resistors should be placed as close as
possible to the smartModule-800PCX.
When the distance between the smartModule-800PCX and connector is greater than 4”, the
terminating resistors should be placed within 1” of the smartModule-800PCX.
When using the ISA reset signal RSTDRV from the smartModule-800PCX, it should be routed through
a Schmitt trigger for RESET# signals.
Ground the following pins of both ATA connectors: 19, 2, 22, 24, 26, 30, and 40.
According to ATA-4 specifications, a 10K Ω pull-down resistor is required on DD7 to allow a host to
recognize the absence of a device at power-up. This pull-down is already on the SM800PC.
Both IDE devices (master and slave) must be connected to IRQ14.
ALE is connected (Pin28) together between the two ATA connectors and is pulled down with a 470
Ω
resistor to meet PC97 requirement.
DIAG (Pin34) is connected together between the two ATA connectors.
33 Ohm series resistors are required on ALL DIE signals We recommend using 33 Ohm and resistor
networks (8 resistors in parallel per part).
Place a 22uF/10V capacitor to each power pin of the interface connector.
The signal length should not be over 100mm.
If master and slave are used, a connection is needed from Pin39 master to Pin39 slave, from Pin34 of
the master to Pin34 of the slave and from Pin20 master to Pin20 of the slave. Plese refer to the
sample schematics.
Pin32 of the DIE-connector must go to the IOCS16# signal.
IDE Interface Signal Resistor Values
Name Termination Resistor ( Ω )
(required externally)
Pull-up (pull-down) Resistor ( Ω )
(already in the module)
DDREQ 33 10K (pull-down)
IORDY 33 None
ALE (Pin28) None 470 (pull-down)
All signals to the
two IDE connectors 33 None
DD7 33 10 K (pull-down)