Datasheet

PDF: 09005aef8202ec2e/Source: 09005aef8202ebf7 Micron Technology, Inc., reserves the right to change products or specifications without notice.
MT9D111__2_REV5.fm - Rev. B 2/06 EN
25 ©2004 Micron Technology, Inc. All rights reserved.
MT9D111 - 1/3.2-Inch 2-Megapixel SOC Digital Image Sensor
Registers and Variables
Micron Confidential and Proprietary
Registers and Variables
Four types of configuration controls are available:
1. Hardware registers
2. Driver variables
3. Special function registers (SFR)
4. MCU SRAM
The following convention is used in the text below to designate registers and variables:
R0x12:1, R0x12:1[3:0] or R18:1, R18:1[3:0]
These refer to two-wire accessible register number 18, or 0x12 hexadecimal, located on
page 1. [3:0] indicate bits. Registers numbers range 0..255 and bits range 15..0.
•ae.Target
This refers to variable ‘Target” in the AE driver.
• SFR 0x1080 or SRAM 0x0400
This refers to special function register or SRAM located at address 0x1080 in MCU
memory space.
How to Access
Registers, variables, and SFRs are accessed in different ways.
Registers
Hardware registers are organized into several pages. Page 0 contains sensor controls.
Page 1 contains color pipeline controls. Page 2 contains JPEG, output FIFO and more
color pipeline controls. The desired page is selected by writing the desired value to
R0xF0. After that all READs and WRITEs to registers 0..255 except R0xF0 and R0xF1, is
directed to the selected page. R0xF0 and R0xF1 are special registers and are present on
all pages. See “Appendix A: Two-Wire Serial Register Interface” on page 180 for descrip-
tion of two-wire register access.
Variables
Variables are located in the microcontroller RAM memory. Each driver, such as auto
exposure, white balance, auto focus, etc., has a unique driver ID (0..31) and a set of pub-
lic variables organized as a structure. Each variable in this structure is uniquely identi-
fied by its offset from the top of the structure and its size. The size can be 1 or 2 bytes,
while the offset is 1 byte.
All driver variables (public and private) can be accessed via R198:1 and R200:1. While
two access modes are available-access by physical address and by logical address, the
public variables are typically accessed by the logical method. The logical address, which
is set in R198:1, consists of a 5-bit driver ID number and a variable offset. Examples are
provided below.
To set the variable ae.Target=50:
• The variable has a driver ID of 2. Therefore, set R198:1[12:8]=2
• The variable has an offset of 6. Therefore, set R198:1[7:0]=6
• This is a logical access. Therefore, set R198:1[14:13]=01
• The size of the variable is 8 bits. Therefore, set R198:1[15]=1
• By combining these bits, R198:1=0xA206.
• Set R200:1=50 for the value of the variable
To read the variable ae.Target:
• Since this is the same variable as the above example, R198:1=0xA206