- 8 × 8 standard keys
- 8 special function keys (SF keys) provide the largest matrix keyboard with a total of 72 keys
-
ACCESS.bus (I 2 C compatible) communication interface to the host
- 4 General Purpose Host Programmable I/O Pins with Two Selectable External Interrupts (Slow)
- A 15-byte FIFO buffer to store key press and key release events
- Error reporting error control (FIFO overflow, overflow keyboard, invalid command)
- Host programmable PWM
- Host programmable active time and bounce time
illustrate
The LM8333 Mobile I/O Helper offloads the scanning keyboard from the host computer, while providing extremely low power consumption in both active and standby modes. It supports a keyboard matrix of 8 × 8 sizes (plus 8 additional special function keys) for portable applications such as mobile phones, PDAs, games, and other handheld applications.
Key press and release events are encoded into a byte format and loaded into a FIFO buffer for retrieval by the host processor. Interrupt output (IRQ) is used for signals such as keyboard activity, state changes on one or two interrupt functions of general-purpose I/O pins, or event of an error condition. Interrupts and error codes are available to the host by reading private registers.
4 general-purpose I/O pins, two of which have interrupt capability. A host-based programmable internal timer pulse-width modulated output is also available, and PWM functionality is not necessary to use as a general-purpose output.
To reduce power consumption, the LM8333 automatically enters a low-power standby mode when there is no keyboard, I/O or host activity.
The device is available in a 32-pin leadless leadframe package (LLP) and a 49-pin microarray. These two chip-scale packages.
apply
- mobile phone
- Personal digital assistants (PDAs, etc.)
- Smart handheld devices
- Personal media player
|