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6399A–DRMSD–13-Oct-08

ATSAM2553

12.5

Scanning Interface

The ATSAM2553 has built-in specialized hardware which allows the following functions:

• Scanning of up to 264 keys from an external keyboard, with key-on and key-off velocity

measurement (time between contacts)

• Scanning of up to 176 switches

• Time multiplex control of up to 88 LEDs

• Analog to digital conversion of up to 16 analog sources

The P16 interfaces with the scanning using a 3 addresses port located at 0CH to 0EH in the I/O

mapping.

This port enables access to the keyboard RAM. This 304 x 11 RAM is mapped as follows:

00H

10H

28H

30H

38H

58H

08H

18H

20H

40H

60H

70H

7FH

Key velocity and status

for MK0/BR0 at row [2:0]

LED data

SWITCH data

ADC data

Key velocity and status

for MK1/BR1 at row [2:0]

Key velocity and status

for MK2/BR2 at row [2:0]

Key velocity and status

for MK3/BR3 at row [2:0]

Key velocity and status

for MK4/BR4 at row [2:0]

Key velocity and status

for MK5/BR5 at row [2:0]

Key velocity and status

for MK6/BR6 at row [2:0]

Key velocity and status

for MK7/BR7 at row [2:0]

Key velocity and status

for MK8/BR8 at row [2:0]

Key velocity and status

for MK9/BR9 at row [2:0]

Key velocity and status

for MK10/BR10 at row

48H

50H

00H

10H

28H

30H

38H

58H

08H

18H

20H

40H

Key velocity and status

for MK0/BR0 at row [2:0]

Key velocity and status

for MK1/BR1 at row [2:0]

Key velocity and status

for MK2/BR2 at row [2:0]

Key velocity and status

for MK3/BR3 at row [2:0]

Key velocity and status

for MK4/BR4 at row [2:0]

Key velocity and status

for MK5/BR5 at row [2:0]

Key velocity and status

for MK6/BR6 at row [2:0]

Key velocity and status

for MK7/BR7 at row [2:0]

Key velocity and status

for MK8/BR8 at row [2:0]

Key velocity and status

for MK9/BR9 at row [2:0]

Key velocity and status for

MK10/BR10 at row [2:0]

48H

50H

00H

10H

28H

30H

38H

58H

08H

18H

20H

40H

Key velocity and status

for MK0/BR0 at row [2:0]

Key velocity and status

for MK1/BR1 at row [2:0]

Key velocity and status

for MK2/BR2 at row [2:0]

Key velocity and status

for MK3/BR3 at row [2:0]

Key velocity and status

for MK4/BR4 at row [2:0]

Key velocity and status

for MK5/BR5 at row [2:0]

Key velocity and status

for MK6/BR6 at row [2:0]

Key velocity and status

for MK7/BR7 at row [2:0]

Key velocity and status

for MK8/BR8 at row [2:0]

Key velocity and status

for MK9/BR9 at row [2:0]

Key velocity and status for

MK10/BR10 at row [2:0]

48H

50H

* Key Page 0

* Key Page 2

* Key Page 1