Datasheet

ADM1069
Rev. C | Page 25 of 32
04735-035
POWER-UP
(V
CC
> 2.5V)
EEPROM
E
E
P
R
O
M
L
D
D
A
T
A
R
A
M
L
D
U
P
D
SMBus
DEVICE
CONTROLLER
LATCH A LATCH B
FUNCTION
(OV THRESHOLD
ON VP1)
Figure 35. Configuration Update Flow Diagram
UPDATING THE SEQUENCING ENGINE
Sequencing engine (SE) functions are not updated in the same
way as regular configuration latches. The SE has its own dedicated
512-byte EEPROM for storing state definitions, providing 63
individual states, each with a 64-bit word (one state is reserved).
At power-up, the first state is loaded from the SE EEPROM into
the engine itself. When the conditions of this state are met, the
next state is loaded from the EEPROM into the engine, and so
on. The loading of each new state takes approximately 10 μs.
To alter a state, the required changes must be made directly to
the EEPROM. RAM for each state does not exist. The relevant
alterations must be made to the 64-bit word, which is then
uploaded directly to the EEPROM.
INTERNAL REGISTERS
The ADM1069 contains a large number of data registers.
The principal registers are the address pointer register and
the configuration registers.
Address Pointer Register
The address pointer register contains the address that selects one
of the other internal registers. When writing to the ADM1069,
the first byte of data is always a register address that is written to
the address pointer register.
Configuration Registers
The configuration registers provide control and configuration
for various operating parameters of the ADM1069.
EEPROM
The ADM1069 has two 512-byte cells of nonvolatile, electrically
erasable, programmable read-only memory (EEPROM), from
Register Address 0xF800 to Register Address 0xFBFF. The
EEPROM is used for permanent storage of data that is not lost
when the ADM1069 is powered down. One EEPROM cell contains
the configuration data of the device; the other contains the state
definitions for the SE. Although referred to as read-only memory,
the EEPROM can be written to, as well as read from, using the
serial bus in exactly the same way as the other registers.
The major differences between the EEPROM and other
registers are as follows:
• An EEPROM location must be blank before it can be
written to. If it contains data, the data must first be erased.
• Writing to the EEPROM is slower than writing to the RAM.
• Writing to the EEPROM should be restricted because it has
a limited write/cycle life of typically 10,000 write operations,
due to the usual EEPROM wear-out mechanisms.
The first EEPROM is split into 16 (0 to 15) pages of 32 bytes each.
Page 0 to Page 6, starting at Address 0xF800, hold the configuration
data for the applications on the ADM1069 (such as the SFDs
and PDOs). These EEPROM addresses are the same as the RAM
register addresses, prefixed by F8. Page 7 is reserved. Page 8 to
Page 15 are for customer use.
Data can be downloaded from the EEPROM to the RAM in one
of the following ways:
• At power-up, when Page 0 to Page 6 are downloaded.
• By setting Bit 0 of the UDOWNLD register (0xD8), which
performs a user download of Page 0 to Page 6.
SERIAL BUS INTERFACE
The ADM1069 is controlled via the serial system management
bus (SMBus) and is connected to this bus as a slave device,
under the control of a master device. It takes approximately
1 ms after power-up for the ADM1069 to download from its
EEPROM. Therefore, access to the ADM1069 is restricted until
the download is complete.
Identifying the ADM1069 on the SMBus
The ADM1069 has a 7-bit serial bus slave address (see Table 11).
The device is powered up with a default serial bus address. The
five MSBs of the address are set to 10011; the two LSBs are
determined by the logical states of Pin A1 and Pin A0. This
allows the connection of four ADM1069s to one SMBus.
Table 11. Serial Bus Slave Address
A1 Pin A0 Pin Hex Address 7-Bit Address
Low Low 0x98 1001100x
1
Low High 0x9A 1001101x
1
High Low 0x9C 1001110x
1
High High 0x9E 1001111x
1
1
x = Read/write bit. The address is shown only as the first 7 MSBs.