Document #: 38-07499 Rev. *F Page 3 of 13
Programming Description
Field Programmable CY25100
The CY25100 is programmed at th e package level, that is, in a
programmer socket. The CY251 00 is Flash based, so the parts
can be reprogrammed up to 100 times. This allows fast and easy
design changes and product updates, and eliminates any issues
with old an d ou t-of-date in ventory.
Samples and small prototype quantities can be programmed on
the CY3672 programmer with CY3690 (TSSOP) or CY3691
(SOIC) socket adapter.
CyberClocks™ Online Software
CyberClocks™ Online Software is a web based software appli-
cation that allows the user to custom-configure the CY25100. All
the parameters in Table 1 given as “Enter Data” can be
programmed into the CY25100. CyberClocks Online outputs an
industry-standard JEDEC file used for programming the
CY25100. CyberClocks Online is available at www.cyberclock-
sonline.com web site through user registration. To register , fill out
the registration form and make sure to check the “non-standard
devices” box. For more information on the registration process
refer to CY3672 data sheet
For information regarding spread spectrum software
programming solutions, contact your local Cypress sales repre -
sentative or Field Application Engineer (FAE).
CY3672 FTG Programming Kit and CY3690/CY3691
Socket Adapter
The Cypress CY3672 FTG programmer and CY3690 and
CY3691 socket adapters are required to program the CY25100.
The CY3690 enables users to program CY25100ZCF and
CY25100ZIF (TSSOP). CY3691 provides the abili ty to program
CY25100SCF and CY25100SIF (SOIC). Each socket adapter
comes with small prototype quantities of CY25100. The CY3690
and CY3691 is a separate orderable item, so the existing use rs
of the CY3672 FTG development kit or CY3672-PRG
programmer need to order only the socket adapters to prog ram
the CY25100.
Factory Programmable CY25100
Factory programming is availab le for volume manufacturing by
Cypress. All requests must be submitted to the local Cypress
Field Application Engineer (FAE) or sales representative. A
sample request form (refer to “CY25100 Sample Request Form”
at www.cypress.com) must be completed. After the request is
processed, you will receive a new part number, samples, and
data sheet with the programmed values. This part number is
used for additional sample requests and production orders.
Additional information on the CY25100 can be obtained from the
Cypress web site at www.cypress.com.
Product Functions
Input Frequency (XIN, Pin 3 and XOUT, Pin 2)
The input to the CY25100 can be a crystal or a clock. The input
frequency range for crystals is 8 to 30 MHz, and for clock signals
is 8 to 166 MHz.
CXIN and CXOUT (Pin 3 and Pin 2)
The load capacitors at Pin 1 (C
XIN
) and Pin 8 (C
XOUT
) can be
programmed from 12 pF to 60 pF with 0.5 pF increments. The
programmed value of these on-chip crystal load capacitors are
the same (XIN = XOUT = 12 t o 60 pF).
The required values of C
XIN
and C
XOUT
are calculated using the
following formula:
C
XIN
= C
XOUT
= 2C
L
– C
P
where C
L
is the crystal load capacitor as specified by the cryst al
manufacturer and C
P
is the parasitic PCB capacitance.
For example, if a fundamental 16 MHz crystal with C
L
of 16 p F is
used and C
P
is 2 pF, C
XIN
and C
XOUT
are calculated as:
C
XIN
= C
XOUT
= (2 x 16) – 2 = 30 pF
If using a driven reference, set C
XIN
and
C
XOUT
to the minimum
value 12 pF.
Output Frequency, SSCLK Output (SSCLK, Pin 7)
The modulated frequency at the SSCLK outp ut is produced by
synthesizing the input reference clock. The modulation can be
stopped by SSON# digital control input (SSON# = HIGH, no
modulation). If modulation is stopped, the clock frequency is the
nominal value of the synthesize d frequency without modulation
(spread percentage = 0). The range of synthesized clock is from
3 to 200 MHz.
Spread Percentage (SSCLK, Pin 7)
The SSCLK spread can be programmed at any percentage value
from ±0.25% to ±2.5% for center spread and from –0.5% to
–5.0% down spread.
Reference Output (REFOUT, Pin 6)
The reference clock output has the same frequency and the
same phase as the input clock. This output can be programmed
to be enabled (clock on) or disabled (High-Z, clock off). If this
output is not required, it is recommended that users request the
disabled (High-Z, Clock Off) option.
Frequency Modulation
The frequency modulation is programmed at 31.5 kHz for all
SSCLK frequencies from 3 to 200 MHz. Contact the factory if a
higher modulation frequency is required.
Power Down or Output Enable (PD# or OE, Pin 4)
The part can be programmed to include either PD# or OE
function. PD# funct i on pow ers do wn the o scill ato r a nd PLL. The
OE function disables the outputs.
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