EZ-USB FX3 Technical Reference Manual, Document Number: 001-76074 Rev. *F 268
GCTL_SPI_CORE_CLK
0xE005202C
10.4.19 GCTL_SPI_CORE_CLK
SPI Core Clock Configuration Register
31 CLK_EN Enable clock divider. Both the divider itself and its output are gated.
18:17 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
16 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 65536.5.
15:0 DIV[15:0] 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 65536.
GCTL_SPI_CORE_CLK SPI Core Clock Configuration Register 0xE005202C
b31 b30 b29 b28 b27 b26 b25 b24
CLK_EN
R/W
R
0
GCTL_SPI_CORE_CLK SPI Core Clock Configuration Register
b23 b22 b21 b20 b19 b18 b17 b16
SRC[1:0] HALFDIV
R/W R/W R/W
RRR
000
GCTL_SPI_CORE_CLK SPI Core Clock Configuration Register
b15 b14 b13 b12 b11 b10 b9 b8
DIV[15:8]
R/W R/W R/W R/W R/W R/W R/W R/W
RRRR
R R R R
GCTL_SPI_CORE_CLK SPI 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