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LM9830 Register Listing

(Registers in bold boxes are reset to that value on power-up. All register addresses are in hexadecimal. All other numbers

are decimal unless otherwise noted.)

Address

Function

D

7

D

6

D

5

D

4

D

3

D

2

D

1

D

0

Value

IMAGE BUFFER (READ ONLY)

00

Pixel (Image) Data

nnn nnnnnOne byte of image data.

STATUS REGISTERS (READ ONLY)

01

Image Data Available In Buffer

nnn nnnnn

n kbytes of image data available

(always read this register twice to make sure its value

was not changing while it was being read)

02

Paper Sensor #1 State

If this input is edge sensitive, reading this

Status Register will clear it.

0False

1True

Paper Sensor #2 State

If this input is edge sensitive, reading this

Status Register will clear it.

0False

1True

Misc I/O #1 State

If this input is edge sensitive, reading this

Status Register will clear it.

0False

1True

Misc I/O #2 State

If this input is edge sensitive, reading this

Status Register will clear it.

0False

1True

Pause

This bit indicates whether or not the scanner

is currently paused due to a buffer full

condition.

0Normal State

1

The scanner entered the pause/reverse cycle during

the processing of this line.

Powerdrop

This bit is used to detect if the power supply

has dipped below 3V since the last time this

register was read. Reading this register

clears this bit.

0

False: Power has not dipped below 3V since the last

time this register was read

1

True: Power has dipped below 3V since the last time

the register was read

DATAPORT REGISTERS

03

DataPort Target

0 Gamma Lookup Table

1 Offset/Gain Coefficient Data (external SRAM)

DataPort Target Color (Note: If using 1

Channel Mode A, the color for the gamma

table is selected by register 26, bits 3 and 4,

not this register)

00

Red

01

Green

10

Blue

11

N/A

04

DataPort Address - MSB

R

/

W

aaaaa

Address of location to be read/written to.

a = 0 to 1023 for gamma tables,

0 to 2729 for Offset/Gain Coefficient Data (300dpi),

0 to 5459 for Offset/Gain Coefficient Data (600dpi).

Addresses greater than these are illegal.

Bit D5 of register 4 indicates whether next operation

will be a Read (D5=1) or a Write (D5=0)

05

DataPort Address - LSB

aaa aaaaa

06

DataPort

nnn nnnnn

Data to be read from or written to the address of the

currently selected Dataport Target. The DataPort

Address is automatically incremented whenever one

(Gamma) or two (Offset/Gain Coefficient Data) bytes

are read from or written to this register.