AD9547/PCBZ Analog Devices Inc, AD9547/PCBZ Datasheet - Page 57

• 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

I/O PROGRAMMING REGISTERS
The register map spans an address range from 0x0000 through
0x0E3F (0 to 3647, decimal). Each address provides access to
one byte (eight bits) of data. Each individual register is iden-
tified by its four-digit hexadecimal address (for example,
Register 0x0A10). In some cases, a group of addresses
collectively define a register (for example, the IRQ mask
register consists of Register 0x0209, Register 0x020A,
Register 0x020B, Register 0x020C, Register 0x020D,
Register 0x020E, Register 0x020F, and Register 0x0210).
In general, when a group of registers defines a control para-
meter, the LSB of the value resides in the D0 position of the
register with the lowest address. The bit weight increases from
right to left, from the lowest register address to the highest
register address. For example, the default value of the incre-
mental phase lock offset step size register (Address 0x0314
to Address 0x0315) is the 16-bit hexadecimal number, 0x03E8
(not 0xE803). Note that the EEPROM storage sequence regi-
sters (Address 0x0E10 to Address 0x0E3F) are an exception
to this convention (see the EEPROM Instructions section).
BUFFERED/ACTIVE REGISTERS
There are two broad categories of registers on the AD9547:
buffered and active (see Figure 63). Buffered registers are
those that can be written to directly from the serial port.
They do not need an I/O update to apply their contents to the
internal device functions. In contrast, active registers
require an I/O update to transfer data between the buffered
registers and the internal device functions. In operation, the
user programs as many buffered registers as desired and then
issues an I/O update. The I/O update is performed by writing
to Register 0x0005, Bit 0 = 1 (or by the external application of
the neces-sary logic level to one of the multifunction pins
previously programmed as an I/O update input). The contents
of the buffered registers that are connected directly to the
internal device functions affect those functions immediately.
The contents of buffered registers that connect to active
registers do not affect the internal device functions until the
I/O update event occurs.
An S or C in the Opt column of the register map identifies
an active register (otherwise, it is a buffered register). An S
entry means that the I/O update signal to the active register is
synchronized with the serial port clock or with an input signal
driving one of the multifunction pins. On the other hand, a
C entry means that the I/O update signal to the active register
is synchronized with a clock signal derived from the internal
system clock (f
When reading back a register that has both buffered and
active contents, Register 0x0004, Bit 0 can be used to select
whether to read back the buffered or active contents. Read-
back of the active contents occurs when Register 0x0004, Bit 0
= 0, whereas readback of the buffered contents occurs when
Register 0x0004, Bit 0 = 1. Note that a read-only active register
requires an I/O update before its contents can be read.
S
/32), as shown in Figure 63.
Rev. B | Page 57 of 104
AUTOCLEARING REGISTERS
An A in the Opt column of the register map identifies an auto-
clearing register. Typically, the active value for an autoclearing
register takes effect following an I/O update. The bit is cleared by
the internal device logic upon completion of the prescribed action.
REGISTER ACCESS RESTRICTIONS
Read and write access to the registers may be restricted, depending
on the register in question, the source and direction of access,
and the current state of the device. Each register can be classified
into one or more access types. When more than one type applies,
the most restrictive condition that applies at that time is used.
When access is denied to a register, all attempts to read the register
return a 0 byte, and all attempts to write to the register are ignored.
Access to nonexistent registers is handled in the same way as for
a denied register.
Regular Access
Registers with regular access do not fall into any other category.
Both read and write access to registers of this type can be from
the serial port or the EEPROM controller. However, only one of
these sources can have access to a register at any given time (access
is mutually exclusive). When the EEPROM controller is active,
either in load or store mode, it has exclusive access to the registers.
Read-Only Access
An R in the Opt column of the register map identifies read-only
registers. Access is available at all times, including when the
EEPROM controller is active.
Exclusion from EEPROM Access
An E in the Opt column of the register map identifies a register
with contents that are inaccessible to the EEPROM. That is, the
contents of this type of register cannot be transferred directly to
the EEPROM or vice versa. Note that read-only registers (R) are
inaccessible to the EEPROM, as well.
SCLK/SCL
CS/SDA
SDIO
SDO
MULTIFUNCTION
5
3
4
2
Figure 63. Buffered and Active Registers
CONTROL
PIN LOGIC
SERIAL
PORT
FROM
DETECT
EDGE
f
S
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AD9547