CY28347
Byte 8: Silicon Signature Register (all bits are Read-only)
Bit
7
6
5
4
3
2
1
0
@Pup
0
0
0
0
1
0
0
0
Name
Revision_ID3
Revision_ID2
Revision_ID1
Revision_ID0
Vender_ID3
Vender_ID2
Vender_ID1
Vender_ID0
Revision ID bit [3]
Revision ID bit [2]
Revision ID bit [1]
Revision ID bit [0]
Cypress’s Vendor ID bit [3]
Cypress’s VendorID bit [2]
Cypress’s Vendor ID bit [1]
Cypress’s Vendor ID bit [0]
Description
Byte9: Dial-A-Frequency Control Register R
Bit
7
6
5
4
3
2
1
0
@Pup
0
0
0
0
0
0
0
0
R5, MSB
R4
R3
R2
R1
R0
DAF_ENB
R and N register mux selection. 0=R and N values come from the ROM. 1=data is
load from DAF (I2C) registers.
Name
Reserved
These bits are for programming the PLL’s internal R register. This access allows
the user to modify the CPU frequency at very high resolution (accuracy). All other
synchronous clocks (clocks that are generated from the same PLL, such as PCI)
remain at their existing ratios relative to the CPU clock.
Description
Dial-a-Frequency Feature
SMBus Dial-a-frequency feature is available in this device via
Byte7 and Byte9.
P is a PLL constant that depends on the frequency selection
prior to accessing the Dial-a-Frequency feature.
Table 9.
FS(4:0)
XXXXX
P
96016000
Spread Spectrum Clock Generation (SSCG)
Spread Spectrum is enabled/disabled via SMBus register Byte
1, Bit 6.
Table 10. Spread Spectrum Table
Mode
0
0
0
0
1
1
1
1
SST1
0
0
1
1
0
0
1
1
SST0
0
1
0
1
0
1
0
1
% Spread
–1.5%
–1.0%
–0.7%
–0.5%
±0.75%
±0.5%
±0.35%
±0.25%
Rev 1.0, November 20, 2006
Page 8 of 21