Appendix D – Accessing The Eeprom - Photon Focus MV-D752-28 User Manual

16 Appendix D – Accessing the EEPROM
The first 4 registers are used for the communication with the configuration EEPROM of
the camera. Register address 0 contains the data, which are written to or read from the
EEPROM. The register 1 contains the LSB of the storage address. The register 2 contains
the MSB of the storage address as well as the accessing code (OP code) for the EEPROM.
The configuration EEPROM has a storage capacity of 2 kB. Therefore the valid storage
addresses are 11 bits (A0 – A10) and range from 000H to 7FFH. After entering the data,
the address and the OP code, all this information is transferred to the EEPROM with the
command SEND_PROM (write register address 3). To read bytes from the EEPROM, the
address and the OP code have to be transferred with the command SEND_PROM to the
EEPROM. The result can than read from register address 0. An overview of the registers
that are used for the EEPROM programming is shown in Table 34.
In order to be able to write to the EEPROM, the write protection must be disabled. The
PROM_BUSY and the AUTOLOAD flag in the EEPROM register address 4 bit 1 or bit 0
must also be checked before writing to the EEPROM. Writing during the BUSY phase leads
to malfunctions of the camera. After writing, the write protection should be enabled
again. This happens automatically when the camera is switched off or loses power.
Table 34: Overview of the register, which are used for the EEPROM
programming
Register address 0 - DATA_EEPROM
bit Name
0 -7 DATA_EEPROM
Register address 1 – ADDR_LSB_EEPROM
bit Name
0 - 7 ADDR_LSB_EEPROM
Register address 2 – ADDR_MSB_EEPROM
bit Name
0 ADDR_MSB_EEPROM
1 ADDR_MSB_EEPROM
2 ADDR_LSB_EEPROM
3 ADDR_LSB_EEPROM
4 ADDR_LSB_EEPROM
5 Not used
6 Not used
7 Not used
Command bit 4
Read 1
Write 0
Write disable 0
Write enable 0
Abbreviations
0: Logical state 0
1: Logical state 1
X: arbitrary state
REV: 1.0
Description
Data bit 0 – 7
Description
Address bit 0 – 7
Description
Address bit 8
Address bit 9 / OP-Code bit 0
Address bit 10 / OP-Code bit 1
OP-Code bit 2
OP-Code bit 3
-
-
-
bit 3 bit 2 bit 1
0 A10 A9
1 A10 A9
0 0 0
0 1 1
MV-D752-28 User's Manual
bit 0
A8
A8
X
X
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