AD9547/PCBZ Analog Devices Inc, AD9547/PCBZ Datasheet - Page 46

• Manufacturer Part Number: AD9547/PCBZ
• Description: Clock Generator/Synchronizer Evaluation Board
• Manufacturer: Analog Devices Inc

Specifications of AD9547/PCBZ

• Silicon Manufacturer: Analog Devices
• Application Sub Type: Network Clock Generator/Synchronizer
• Kit Application Type: Clock & Timing
• Silicon Core Number: AD9547
• Main Purpose: Timing, Clock Generator
• Embedded: No
• Utilized Ic / Part: AD9547
• Primary Attributes: 2 Differential or 4 Single Ended Inputs
• Secondary Attributes: CMOS, LVPECL & LVDS Compatible
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD9547
EEPROM
EEPROM Overview
The AD9547 contains an integrated 2048-byte electrically erasable
programmable read-only memory (EEPROM). The AD9547
can be configured to perform a download at power-up via the
multifunction pins (M3 to M7), but uploads and downloads
can also be done on demand via the EEPROM control registers
(Address 0x0E00 to Address 0x0E03).
The EEPROM provides the ability to upload and download
configuration settings to and from the register map. Figure 47
shows a functional diagram of the EEPROM.
Register 0x0E10 to Register 0x0E3F represent a 48-byte scratch
pad that enables the user to store a sequence of instructions for
transferring data to the EEPROM from the device settings portion
of the register map. Note that the default values for these registers
provide a sample sequence for saving/retrieving all of the AD9547
EEPROM-accessible registers. Figure 47 shows the connectivity
between the EEPROM and the controller that manages data
transfer between the EEPROM and the register map.
The controller oversees the process of transferring EEPROM data
to and from the register map. There are two modes of operation
handled by the controller: saving data to the EEPROM (upload
mode) or retrieving data from the EEPROM (download mode).
In either case, the controller relies on a specific instruction set.
EEPROM Instructions
Table 27 lists the EEPROM controller instruction set. The
controller recognizes all instruction types, whether it is in
upload or download mode, except for the pause instruction,
which it recognizes only in upload mode.
The I/O update, calibrate, distribution sync, and end instruc-
tions are mostly self-explanatory. The others, however, warrant
further detail, as described in the following paragraphs.
Data instructions are those that have a value from 0x00 to 0x7F.
A data instruction tells the controller to transfer data between
the EEPROM and the register map. The controller needs the
following two parameters to carry out the data transfer:
•
•
M7
M6
M5
M4
M3
SETTINGS
ADDRESS
POINTER
DEVICE
(0x0100 TO 0x0A10)
DEVICE SETTINGS
The number of bytes to transfer
The register map target address
Figure 47. EEPROM Functional Diagram
REGISTER MAP
CONTROLLER
EEPROM
(0x0E10 TO 0x0E3F)
SCRATCH PAD
SCRATCH PAD
ADDRESS
POINTER
ADDRESS
POINTER
EEPROM
DATA
INPUT/OUTPUT
(0x000 TO 0x7FF)
SERIAL
PORT
EEPROM
Rev. B | Page 46 of 104
The controller decodes the number of bytes to transfer directly
from the data instruction itself by adding one to the value of the
instruction. For example, the data instruction, 0x1A, has a decimal
value of 26; therefore, the controller knows to transfer 27 bytes
(one more than the value of the instruction). Whenever the con-
troller encounters a data instruction, it knows to read the next
two bytes in the scratch pad because these bytes contain the
register map target address.
Note that, in the EEPROM scratch pad, the two registers that
make up the address portion of a data instruction have the MSB of
the address in the D7 position of the lower register address. The
bit weight increases left to right, from the lower register address
to the higher register address. Furthermore, the starting address
always indicates the lowest numbered register map address in the
range of bytes to transfer. That is, the controller always starts at
the register map target address and counts upward, regardless of
whether the serial I/O port is operating in I
SPI MSB first mode.
As part of the data transfer process during an EEPROM upload,
the controller calculates a 1-byte checksum and stores it as the final
byte of the data transfer. As part of the data transfer process during
an EEPROM download, however, the controller again calculates
a 1-byte checksum value but compares the newly calculated check-
sum with the one that was stored during the upload process. If an
upload/download checksum pair does not match, the controller
sets the EEPROM fault status bit (Register 0x0D03, Bit 1). If the
upload/download checksums match for all data instructions
encountered during a download sequence, the controller sets
the EEPROM complete status bit (Register 0x0D03, Bit 0).
Condition instructions are those that have a value from 0xB0 to
0xCF. Condition Instruction 0xB1 to Condition Instruction 0xCF
represent Condition 1 to Condition 31, respectively. Condition
Instruction 0xB0 is special because it represents the null condition
(see the EEPROM Conditional Processing section).
A pause instruction, like an end instruction, is stored at the end
of a sequence of instructions in the scratch pad. When the control-
ler encounters a pause instruction during an upload sequence,
it keeps the EEPROM address pointer at its last value. This way,
the user can store a new instruction sequence in the scratch pad
and upload the new sequence to the EEPROM. The new sequence
is stored in the EEPROM address locations immediately following
the previously saved sequence. This process is repeatable until
an upload sequence contains an end instruction. The pause
instruction is also useful when used in conjunction with condition
processing. It allows the EEPROM to contain multiple occurrences
of the same register(s), with each occurrence linked to a set of
conditions (see the EEPROM Conditional Processing section).
2
C, SPI LSB first, or