8. Register Map
All Si5357 registers are listed in the table below. The fields in this table are the register field name, address, base, bit length, “R/W/RW”,
description, and device mode. Note that all registers hold values that are "big-endian", i.e., bit 7 is the MSB in an eight-bit field.
The definitions for these fields are:
1.
Register Field Name
: The name for the register field in this FRM as referenced in the tables below and in other sections in this
FRM.
2.
Address
: The 8-bit register address to be used in the I
2
C transactions when the register field needs to be addressed.
3.
Base
: Every register field address addresses an 8-bit wide location. However, the register field may not occupy that entire location.
In those cases, they may also not start at the LSB i.e. bit #0 of that location. Base provides the bit #i from which this register field
begins in the addressed location.
4.
Bit Length
: Bit length indicates the “number of bits” that the register field occupies in the addressed location
5.
R/W/RW
: This field indicates if the register field is Read only (R), Write only (W) or Read/Write (RW).
6.
Description
: Description is an explanation on the purpose and programmability offered by the register field.
7. I: Device mode is the mode of Si5357 in which the register field can be accessed. Si5357 has two modes of function “READY”
where the Si5357 is ready for programming in which time there will no outputs from Si5357 and “ACTIVE” where the Si5357 is
actively locked to an input and is providing outputs. Some register fields can be programed in either READY or ACTIVE mode
(READY/ACTIVE) whereas others can only be programmed in READY mode (READY). Device mode provides input on which
mode applies to a register field a user intends to modify.
Table 8.1. Si5357 Register Map
Register field name
Address Base
Bit
length
R/W/RW
Description
Device
mode
VDD_XTAL_OK
5
7
1
R
Flag that VDD_XTAL is greater than its
minimum level, which is about 1.5 V.
READ/
ACTIVE
VDDO_OK
5
0
6
R
Flags that varios various VDDO supplies
are greater than their minimum level,
which is about 1.2 V.
USYS_CTRL
6
0
8
RW
User system control. Write 0x01h to make
the part READY. Write 0x02h to make the
part ACTIVE
READY/
ACTIVE
USYS_STAT
7
0
8
R
User system status. This indicates the sta-
tus of the application, and what state it
is in, like READY, ACTIVE, etc. It is read
only register for I2C
READY/
ACTIVE
UDRV_OE_ENA
8
0
1
RW
User master output enable. Resets to 1.
This bit controls simultaneously the driver
start for all drivers.
READY/
ACTIVE
USER_SCRATCH0
9
0
8
RW
User scratch pad registers, freely R/W any
time. This is just run time cratch area, not
initialized from NVM. The reset value is
0x00 for all bytes. Can be I2C read and
written any time.
READY/
ACTIVE
USER_SCRATCH1
A
0
8
RW
USER_SCRATCH2
B
0
8
RW
USER_SCRATCH3
C
0
8
RW
Si5357 Reference Manual • Register Map
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
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Rev. 0.2 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • July 26, 2021
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