STEVAL-TCS003V1 STMicroelectronics, STEVAL-TCS003V1 Datasheet - Page 46

• Manufacturer Part Number: STEVAL-TCS003V1
• Description: BOARD DEMO EXPANDER STMPE2403
• Manufacturer: STMicroelectronics

Specifications of STEVAL-TCS003V1

• Main Purpose: Interface, GPIO Expander
• Embedded: No
• Utilized Ic / Part: STMPE2403
• Primary Attributes: 8/16/24-Bit 24-Port GPIO Expander over I2C
• Secondary Attributes: 3 8-Bit PWM Output for LEDs, Keyboard Matrix Scan, Special Key Support
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-8206

Keypad controller
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Keypad controller
The keypad controller consists of: 1) four dedicated key controllers that support up to four
simultaneous dedicated key presses; 2) a key scan controller and two normal key controllers
that support a maximum of 12x8 key matrix with detection of three simultaneous key
presses; 3) eight special function key controllers that support up to eight simultaneous
special function key presses.
Four of the column inputs can be configured as dedicated keys through the setting of
Dkey0~3 bits of KPC_ctrl register.
The normal key matrix size is configurable through the setting of KPC_row and KPC_col
registers. The scanning of each individual row output and column input can be enabled or
masked to support a key matrix of variable size from 1x1 to 12x8. It is allowed to have
another eight special function keys incorporated in the key matrix.
The operation of the keypad controller is enabled by the SCAN bit of KPC_ctrl register.
Every key activity detected will be de-bounced for a period set by the DB_0~7 bits of
KPC_ctrl register before a key press or key release is confirmed and updated into the output
FIFO. The key data, indicating the key coordinates and its status (up or down), is loaded into
the FIFO at the end of a specified number of scanning cycles (set by ScanCount0~3 bits of
KPC_row_msb register). An interrupt will be generated when a new set of key data is
loaded. The FIFO has a capacity for ten sets of key data. Each set of key data consists of 5
bytes of information when any of the four dedicated keys is enabled. It is reduced to 4 bytes
when no dedicated key is involved. When the FIFO is full before its content is read, an
overflow signal will be generated while the FIFO will continue to hold its content but forbid
loading of new key data set.
Figure 8.
Input 0-7
Keypad controller
Keypad Matrix
Output 0-11
STMPE2403