19

ATSAM9753

1774D–DRMSD–11/02

RAM Data

DataL[7:0]

I/O address ODH, Data[7:0]

DataH[2:0]

I/O address OEH, Data[10:8]

DataH[7:3]

don't care

•

Key Velocity and Status:

–

SRQ: If 1, indicates that the velocity detection is complete and that this key

requests attention from the P16. In this case BUSY = 0, ON and TIME hold

valid information.

–

ON: 1 indicates key-on, 0 indicates key-off. Valid only if SRQ = 1.

–

BUSY: Used internally by the scanning hardware, indicates “velocity

detection in progress”.

–

TIME: From 0 to 255, valid only if SRQ = 1, indicates the time between

contacts in multiples of 45 µs. Set to 255 if the time is greater or equal to

256*45 µs.

•

LED Data: The P16 should write to these locations the MK information which should

appear to the MK[10:0] pins at ROW[2:0] time.

•

Switch Data: These fields hold the BR information read from the BR[10:0] pins at

ROW[3:0] time.

•

ADC Status: These fields represent the analog voltage at VIN pin at ROW[3:0] time,

from 0 (VIN = VREFN) to 0FFH (VIN = VREFP).

Table 15. Scanning RAM Data Format

Bit

10

98

7654

321

0

Key Velocity and Status

SRQ

ON

BUSY

TIME

LED Data

MK10

MK9

MK8

MK7

MK6

MK5

MK4

MK3

MK2

MK1

MK0

Switch Data

BR10

BR9

BR8

BR7

BR6

BR5

BR4

BR3

BR2

BR1

BR0

ADC Status

X

X

X

ADC DATA