4

ATSAM9753

1774D–DRMSD–11/02

BR[10:0]

1 - 3, 135 - 138, 141 - 144

IN

Keyboard contact 1/switch status. When KBDIO = 1 then BR[10:0] holds the

keyboard key-off or first contact status. This can be configured as normally

closed (spring type), normally open (rubber type), common anode or

common cathode contact diodes. When KBDIO = 0 then BR[10:0] holds the

switch status from ROW[2:0] or ROW[3:0].

MK[10:0]

120 - 124,127, 128,

131 - 134

I/O

Keyboard contact 2/LED data. When KBDIO =1 then MK[10:0] holds the

keyboard key-on or second contact status. This can be configured as

common anode or common cathode contact diodes.When KBDIO = 1 then

MK[10:0] holds the led data from ROW[2:0].

VREFP

106

ANA

Positive reference voltage. Should normally be connected to a clean AV

C3

supply.

VREFN

105

ANA

Negative reference voltage. Should normally be connected to a clean AGND.

VIN

104

ANA

Slider analog input. Ranges from VREFN to VREFP. Should hold the

ROW[2:0] or ROW[3:0] slider voltage. Multiple sliders should be connected

through external analog multiplexer(s) like 4051.

LCD Display Interface

(2)

RS

16

OUT

Select instruction (LOW) or data (HIGH).

RW

15

OUT

Select write (LOW) or read (HIGH).

ENB

14

OUT

Enable, active high.

DB[7:0]

6 - 13

I/O

Bi-directional data bus.

Digital Audio Group

(3)

DACLK

93

OUT

Master clock for sigma-delta DAC (256 x Fs).

DABD[1:0]

89, 92

OUT

Serial data for two stereo output channels.

DAAD

88

IN

Serial data for one stereo input channel.

CLBD

86

OUT

Digital audio bit clock.

WSBD

87

OUT

Digital audio left/right select.

Miscellaneous Pins

GPIO[4:0]

108, 109, 112 - 114

I/O

These pins can be used individually as general-purpose I/Os or as alternate

functions. When used as general-purpose I/Os, they can be individually

configured as inputs or outputs. When used as alternate functions their

meaning changes as follows:

GPIO0 = ROW3 expands switches to 176, sliders to 16

GPIO2 = DBCLK (input)

GPIO3 = DBACK (output)

GPIO4 = DBDATA (I/O) (DBDATA input = DBIN, DBDATA output = DBOUT)

DBCLK, DBACK, DBDATA are used for debugging or external Flash memory

programming when DEBUG is low

DEBUG

85

IN

Configuration pin, low for CodeView debugging/external Flash memory

programming. Should be tied to V

RESET

83

IN

Reset input, active low. This is a Schmitt trigger input, allowing direct

connection of a RC network.

RUN

118

OUT

Indicates that the DSP is up and running. Can be used as external DAC

reset.

Table 1. Pin Description by Function (Continued)

Pin Name

Pin Number

Type

Function