NJU6010 Просмотр технического описания (PDF) - Japan Radio Corporation

Номер в каталоге

Компоненты Описание

Список матч

NJU6010

24 keys input key-scan IC

Japan Radio Corporation  

Preliminary NJU6010

(2-3) Example of Key-scan Data Output

When CSb="L", the key data is output in order of "dummy → KD1~KD24 → dummy" from DATA

terminal by the falling edge of SCL (Refer to Fig. 5). Therefore, the key data reading with CPU is fetched

by the rising edge of SCL. When the CSb is falling edge, NJU6010 reads the key data regardless of the

state of SCL ("H" or "L") (Refer to Fig. 5 (1) (2)). In case of (1), the 1st dummy data is not read with CPU.

In case of (2), it is necessary to read the 1st dummy data. Therefore, the setting to read the dummy data

with CPU is necessary.

The key data is output as 24-bit of KD1~KD24. The bit corresponding to the pressed key is output as

"H", and the other bits are output as "L". (Refer to (2-4) The Relation Between Key Matrix and Key Data.)

When the CSb="H", NJU6010 outputs the key data reading request as becoming the DATA="H" (REQ

flag). After this REQ flag is checked, the key data requires reading. In case of reading the key data in the

state of the CSb="H" and DATA="L", the unexpected data is output.

After finished reading of the key data in CPU, read-out of key data is released by CSb="H", and

NJU6010 waits for the next key input. When the CSb="H" before reading 24 bits of all the key data, the

key data in a register is lost, a REQ flag is also released, and NJU6010 waits for the next key input.

(1) In case of SCL=”H”

CSb

SCL

DATA REQ * KD1 KD2 KD3

KD21

KD22

KD23

KD24

*

This dummy data cannot be read in CPU.

* : Dummy data

(2) In case of SCL=”L”

CSb

SCL

DATA REQ *

KD1 KD2 KD3

KD21

KD22

This dummy data cannot be read in CPU.

KD23

KD24

*

* : Dummy data

Fig. 5 Key Data Transfer Timing

Ver.2009-08-20

-5-

Share Link: