73S8009R Data Sheet
DS_8009R_056
Deactivation is initiated either by the system controller setting CMDVCC#/CMDVCC% high, or
automatically in the event of hardware faults. Hardware faults are over-current, over-temperature and
card extraction during the session. The host can manage the I/O signals, CLKIN, RSTIN, and
CMDVCC#/CMDVCC% to create other de-activation sequences for non-emergency situations.
~ 100 µs
CMDVCC% or CMDVCC#
VCC
5 - VCC is lowered
I/OUC
4 - I/O falls approx 2 µs after CLK falls
I/O
OFF
1 - OFF falls due to card removal or fault
RSTIN
RST
2 - RST forced low approx. 0.6 µs after OFF falls
CLKIN
CLK
3 - CLK forced low approx. 7.5 µs after RST falls
Note: Host should set STROBE low when OFF goes low, otherwise CLK may be truncated
Figure 6: Deactivation Sequence
3.7 OFF and Fault Detection
The system controller can monitor the OFF signal to:
•
•
Query regarding the card presence outside of a card session
Detect faults during card sessions.
Outside a Card Session
In this condition, CMDVCC#/CMDVCC%) is always high, OFF is low if the card is not present and high if
the card is present. Because it is outside a card session, any fault detection will not act upon the OFF
signal. No deactivation is required during this time.
During a Card Session
In this condition, CMDVCC#/CMDVCC% is always low and OFF falls low if the card is extracted or if any
fault is detected. At the same time that OFF is set low, the sequencer automatically starts the
deactivation process and the host should stop all transition on the signal lines.
Figure 7 shows the timing diagram for the signals CMDVCC#, CMDVCC%, PRES and OFF during a card
session and outside the card session.
16
Rev. 1.3
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
