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2.1 Preparing the SMextend 750 for use
2.1 Preparing the SMextend 750 for use
As shipped from the factory the SMextend 750 is configured with voltage keys disabled. In this condition, the
SMextend may not be accepted into many SmartMedia sockets. The SmartMedia standard defines two voltage keys,
one for 3.3V and one for 5V. 3.3V only cards have a cutout corner adjacent to pin 22 of the connector. 5V only
cards have a cutout adjacent to pin 12. Cards that can operate at both 3.3V and 5V have both cutouts. The following
section describes how to configure the SMextend for the desired operating voltage.
2.1.1 Removing the voltage key.
2.1.1 Removing the voltage key.
The 3V key should be removed if the card is to be used in a 3.3V host. The 5V key should be removed for 5V hosts.
The voltage key can be removed with a small pair of pliers or a wire cutter. The SMextend 750 PCB is scored along
the proper cut marks. After the user removes the keys, it may be necessary to clean the freshly cut edge of the board
with a small file. Some sockets may not accept the SMextend 750 if these edges are not smooth.
Note: Once removed, the voltage keys cannot be reattached.
Note
2.2 Using the SMextend
2.2 Using the SMextend
Use of the SMextend 750 is fairly straightforward. The SMextend is inserted into the host socket with the connector
pattern in the correct orientation. The SmartMedia card is then inserted, with the connector pattern facing down, into
SMextend 750's socket.
Caution: The SMextend socket is keyed to accept both 3.3V and 5V SmartMedia cards. This configuration
Caution
could allow a 3.3V only card to be plugged into a 5V host causing damage to either the card or the host. The
user should verify compatibility by first trying to inserting the SmartMedia card into the host prior to using
the extender card.
2.3 Test points
2.3 Test points
All 22-pins of the interface are available to probe through clearly marked headers.
dual row headers with 0.025" posts designed to accept a wide variety of test probes and cable assemblies.
2.4 Power Indicators
2.4 Power Indicators
Two LED power indicators display the status of the socket's Vcc. The PWR LED indicates that power is applied to
the board. When both the PWR LED and the 5V LED are lit, a Vcc of greater than approximately 3.5V is present.
When only the PWR LED is lit, the Vcc is at a level of less than 3.5V.
Note: The power LEDs are designed to indicate the presence of power on the Vcc supply pins. The LEDs
Note
do not provide an accurate measurement of Vcc. Use a voltmeter to determine the actual operating voltage.
In some low power applications, the current drawn by the power LEDs (10-20mA) may cause problems. The
SMextend is capable of disabling the LED voltage indication by removing the jumper labeled LED EN at JP4.
2.5 Current Measurements
2.5 Current Measurements
The Vcc power bus may be isolated from the SmartMedia Card socket through two jumper blocks labeled JP2 and
JP3. Both jumpers must be removed to isolate the power. A current meter can be inserted to measure card current
consumption.
Caution: Care must be taken to insure that the current measuring device is inserted before turning on power
Caution
to the host socket. Improper power sequencing may cause a damaging latchup condition.
1998 Sycard Technology
SMextend 750 User's Manual
The headers are standard 0.1"
M200042-00
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