73S1209F Data Sheet
DS_1209F_004
Card Status/Control Register (CRDCtl): 0xFE05
Å
0x00
This register is used to configure the card detect pin (DETCARD) and monitor card detect status. This
register be written to properly configure Debounce, Detect_Polarity (= 0 or = 1), and the pull-up/down
enable before setting CDETEN. The card detect logic is functional even without smart card logic clock.
When the PWRDN bit is set = 1, no debounce is provided but card presence is operable.
Table 78: The CRDCtl Register
MSB
LSB
DEBOUN CDETEN
–
–
DETPOL
PUENB PDEN CARDIN
Bit Symbol
Function
CRDCtl.7 DEBOUN
Debounce – When set = 1, this will enable hardware de-bounce of the
card detect pin. The de-bounce function shall wait for 64ms of stable card
detect assertion before setting the CARDIN bit. This counter/timer uses
the keypad clock as a source of 1kHz signal. De-assertion of the CARDIN
bit is immediate upon de-assertion of the card detect pin(s).
CRDCtl.6 CDETEN
Card Detect Enable – When set = 1, activates card detection input.
Default upon power-on reset is 0.
CRDCtl.5 –
CRDCtl.4 –
CRDCtl.3 DETPOL
Detect Polarity – When set = 1, the DETCARD pin shall interpret a logic 1
as card present.
CRDCtl.2
PUENB
Enable pull-up current on DETCARD pin (active low).
CRDCtl.1 PDEN
Enable
pull-down
current on DETCARD pin.
CRDCtl.0 CARDIN
Card Inserted – (Read only). 1 = card inserted, 0 = card not inserted. A
change in the value of this bit is a “card event.” A read of this bit indicates
whether smart card is inserted or not inserted in conjunction with the
DETPOL setting.
84
Rev.
1.2