Cypress EZ-USB FX3 User Manual

EZ-USB FX3 Technical Reference Manual, Document Number: 001-76074 Rev. *F 266
GCTL_I2C_CORE_CLK
0xE0052020
10.4.17 GCTL_I2C_CORE_CLK
I
2
C Core Clock Configuration Register
This register contains the divider for the I
2
C clock block. It must be set to a frequency that is 10x the bit rate on the interface
(so 1 MHz, 4 MHz, 10 MHz, and so on).
31 CLK_EN Enable clock divider. Both the divider itself and its output are gated.
14:13 SRC[1:0] Clock source select. This field selects between one of the following four prestage system clocks:
00 sys16_clk (sys_clk_pll divided by 16)
01 sys4_clk (sys_clk_pll divided by 4)
10 sys2_clk (sys_clk_pll divided by 2)
11 sys_clk_pll
12 HALFDIV Nonintegral divider select. This field adds 0.5 to the divider value selected by the DIV field. This yields
divider values from 2.5 to 4096.5.
11:0 DIV[11:0] Clock divider value. This determines how much to divide the PLL system clock. The actual divider is
DIV + 1. Zero (divide by 1) is illegal and results in undefined behavior. In other words, the range of
divider values is 2 to 4096.
GCTL_I2C_CORE_CLK
I
2
C Core Clock Configuration Register
0xE0052020
b31 b30 b29 b28 b27 b26 b25 b24
CLK_EN
R/W
R
0
GCTL_I2C_CORE_CLK
I
2
C Core Clock Configuration Register
b23 b22 b21 b20 b19 b18 b17 b16
GCTL_I2C_CORE_CLK
I
2
C Core Clock Configuration Register
b15 b14 b13 b12 b11 b10 b9 b8
SRC[1:0] HALFDIV DIV[11:8]
R/W R/W R/W R/W R/W R/W R/W
RRRR R R R
000
GCTL_I2C_CORE_CLK
I
2
C Core Clock Configuration Register
b7 b6 b5 b4 b3 b2 b1 b0
DIV[7:0]
R/W R/W R/W R/W R/W R/W R/W R/W
R R R R R R R R
1
Bit Name Description

Cypress EZ-USB FX3 Specifications

General

Brand	Cypress
Model	EZ-USB FX3
Category	Controller
Language	English