CY22150
Document #: 38-07104 Rev. *I
Page 4 of 16
Default Startup Condition for the CY22150
The default (programmed) condition of the device is generally set
by the distributor who programs the device using a customer
specific JEDEC file produced by CyClocksRT
™. Parts shipped
from the factory are blank and unprogrammed. In this condition,
all bits are set to 0, all outputs are three-stated, and the crystal
oscillator circuit is active.
While you can develop your own subroutine to program any or
all of the individual registers described in the following pages, it
may be easier to use CyClocksRT to produce the required
register setting file.
The serial interface address of the CY22150 is 69H. If there is a
conflict with any other devices in your system, then this can also
be changed using CyClocksRT.
Frequency Calculations and Register Defini-
tions using the Serial Programming Interface
The CY22150 provides an industry standard serial interface for
volatile, in-system programming of unique frequencies and
options. Serial programming and reprogramming allows for quick
design
changes
and
product
enhancements,
eliminates
inventory of old design parts, and simplifies manufacturing.
The Serial Programming Interface (SPI) provides volatile
programming. This means when the target system is powered
down, the CY22150 reverts to its pre-SPI state, as defined above
(programmed or unprogrammed). When the system is powered
back up again, the SPI registers must be reconfigured again.
All programmable registers in the CY22150 are addressed with
eight bits and contain eight bits of data. The CY22150 is a slave
device with an address of 1101001 (69H).
Table 2 lists the SPI registers and their definitions. Specific
register definitions and their allowable values are listed below.
Reference Frequency
The REF can be a crystal or a driven frequency. For crystals, the
frequency range must be between 8 MHz and 30 MHz. For a
driven frequency, the frequency range must be between 1 MHz
and 133 MHz.
Using a Crystal as the Reference Input
The input crystal oscillator of the CY22150 is an important
feature because of the flexibility it allows the user in selecting a
crystal as a REF source. The input oscillator has programmable
gain, allowing maximum compatibility with a reference crystal,
regardless of manufacturer, process, performance, and quality.
Programmable Crystal Input Oscillator Gain Settings
The Input crystal oscillator gain (XDRV) is controlled by two bits
in register 12H and are set according to Table 3 on page 5. The
parameters controlling the gain are the crystal frequency, the
internal crystal parasitic resistance (ESR, available from the
manufacturer), and the CapLoad setting during crystal startup.
Bits 3 and 4 of register 12H control the input crystal oscillator gain
setting. Bit 4 is the MSB of the setting, and bit 3 is the LSB. The
setting is programmed according to Table 3 on page 5. All other
bits in the register are reserved and should be programmed as
shown in Table 4 on page 5.
Using an External Clock as the Reference Input
The CY22150 also accepts an external clock as reference, with
speeds up to 133 MHz. With an external clock, the XDRV
(register 12H) bits must be set according to Table 5 on page 5.
Table 2. Summary Table – CY22150 Programmable Registers
Register
Description
D7
D6
D5
D4
D3
D2
D1
D0
09H
CLKOE control
0
0
CLK6
CLK5
LCLK4
LCLK3
LCLK2
LCLK1
OCH
DIV1SRC mux and
DIV1N divider
DIV1SRC
DIV1N(6)
DIV1N(5)
DIV1N(4)
DIV1N(3)
DIV1N(2)
DIV1N(1)
DIV1N(0)
12H
Input crystal oscillator
drive control
0
0
1
XDRV(1)
XDRV(0)
0
0
0
13H
Input load capacitor
control
CapLoad
(7)
CapLoad
(6)
CapLoad
(5)
CapLoad
(4)
CapLoad
(3)
CapLoad
(2)
CapLoad
(1)
CapLoad
(0)
40H
Charge pump and PB
counter
1
1
0
Pump(2)
Pump(1)
Pump(0)
PB(9)
PB(8)
41H
PB(7)
PB(6)
PB(5)
PB(4)
PB(3)
PB(2)
PB(1)
PB(0)
42H
PO counter, Q counter
PO
Q(6)
Q(5)
Q(4)
Q(3)
Q(2)
Q(1)
Q(0)
44H
Crosspoint switch
matrix control
CLKSRC2
for LCLK1
CLKSRC1
for LCLK1
CLKSRC0
for LCLK1
CLKSRC2
for LCLK2
CLKSRC1
for LCLK2
CLKSRC0
for LCLK2
CLKSRC2
for LCLK3
CLKSRC1
for LCLK3
45H
CLKSRC0
for LCLK3
CLKSRC2
for LCLK4
CLKSRC1
for LCLK4
CLKSRC0
for LCLK4
CLKSRC2
for CLK5
CLKSRC1
for CLK5
CLKSRC0
for CLK5
CLKSRC2
for CLK6
46H
CLKSRC1
for CLK6
CLKSRC0
for CLK6
11
111
1
47H
DIV2SRC mux and
DIV2N divider
DIV2SRC
DIV2N(6)
DIV2N(5)
DIV2N(4)
DIV2N(3)
DIV2N(2)
DIV2N(1)
DIV2N(0)
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