73S1210F Datasheet, PDF (63/126 Pages) Teridian Semiconductor Corporation – Self-Contained Smart Card Reader with PINpad and Power Management

DS_1210F_001
Keypad
Initialization
All Column
Outputs = 0
73S1210F Data Sheet
KSTAT Register:
Enable HW Scanning
Enable Keypad Interrupt
Any
Row
Input = 0 ?
No
Yes
No
Deboucing
KSCAN Register:
Timer
Debouncing Time
Any Row
Input still = 0 ?
KORDERL / H Registers:
Column Scan Order
Keypad Scanning
KSIZE Register:
Keypad Size Definition
KSCAN Register:
Scanning Rate
More
than
1 key
How Many
keys have been
detected?
0 key
1 key
Download of the key row and
column values in KROW and
KCOL registers
KCOL Register:
Value of the valid key column
KROW Register:
Value of the valid key row
Keypad Interrupt
generation
KSTAT Register:
Key Detect Interrupt
No
Deboucing
Timer
Is (are)
the key(s)
still released ?
(*)
Yes
Is (are)
Yes
the key(s)
released ?
(*)
KSCAN Register:
Debouncing Time
No
Register Used to Control the
hardware keypad interface
Register written by the
hardware keypad interface
(*) Key release is cheked by looking for a low level on any row.
Figure 13: Keypad Interface Flow Chart
Rev. 1.4
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