Device Under Test
10
SNAU236A – June 2018 – Revised December 2018
Copyright © 2018, Texas Instruments Incorporated
LMK05318EVM User's Guide
2
Device Under Test
The evaluation module is shipped with the LMK05318 DUT (U5) soldered down. The pin 1 position of the
48-pin QFN package is indicated by a dot symbol in top silkscreen. Alternatively, the U5 can be
unmounted and a test socket (XU1) can be populated. See for the socket part number. TI recommends
populating the socket with the hinge on the left-hand side (towards OUT[0:3] ports) and the latch on the
right-hand side.
2.1
Device Start-Up Modes
The LMK05318 can start-up in one of three modes depending on the 3-level input level sampled on the
HW_SW_CTRL pin upon power-on reset (POR). The start-up modes are listed in
and determine
the following:
1. The memory bank (EEPROM or ROM) used to initialize the registers upon start-up.
2. The serial interface (I
2
C or SPI) used for register access.
3. The logic pin definitions.
The I
2
C or SPI interface allows for register access to configure the device after start-up and monitor its
status. The register map configurations are the same for I
2
C and SPI.
See
for detailed descriptions of the logic pins for each start-up mode.
(1)
The input levels on these pins are sampled only during POR.
(2)
FINC and FDEC pin controls are only available when DCO mode and GPIO pin control are enabled by registers.
Table 4. Device Start-Up Modes
HW_SW_CTRL
(1)
INPUT LEVEL
START-UP MODE
MODE DESCRIPTION
0
I
2
C
(Soft pin mode)
Registers are initialized from EEPROM, and I
2
C interface is enabled with slave
address 11001xxb. Logic pins:
• SDA/SDI, SCL/SCK: I
2
C Data, I
2
C Clock
• GPIO0/SYNCN: Output Sync (active low)
• GPIO1/SCS
(1)
: I
2
C Address LSB Select (Low = 00b, Float = 01b, High = 10b)
• GPIO2/SDO/FINC
(2)
: DPLL DCO Frequency Increment (active high)
• STATUS1/FDEC
(2)
: DPLL DCO Frequency Decrement (active high), or Status
output
Float
(V
IM
)
SPI
(Soft pin mode)
Registers are initialized from EEPROM, and SPI interface is enabled. Logic pins:
• SDA/SDI, SCL/SCK: SPI Data In (SDI), SPI Clock (SCK)
• GPIO0/SYNCN: Output Sync (active low)
• GPIO1/SCS: SPI Chip Select (SCS)
• GPIO2/SDO/FINC: SPI Data Out (SDO)
1
ROM + I
2
C
(Hard pin mode)
Registers are initialized from the ROM page selected by GPIO pins, and I
2
C interface
is enabled with the 7-bit slave address of 0x64. Logic pins:
• SDA/SDI, SCL/SCK: I
2
C Data, I
2
C Clock
• GPIO[2:0]
(1)
: ROM page select at POR
• After POR, GPIO2/SDO/FINC and STATUS1/FDEC pins can function the same
as for HW_SW_CTRL = 0 if enabled by registers.
TI suggests to use the EEPROM mode when either of the following is true:
•
A single custom start-up frequency configuration is required from a single OPN.
•
A host device is able to program the registers (and EEPROM, if needed) with a new configuration after
power-up through I
2
C or SPI. SPI is not supported by ROM mode.