Cypress CY7C601xx Network Card User Manual


 
CY7C601xx, CY7C602xx
Document 38-16016 Rev. *E Page 23 of 68
Figure 12-1. CPU Clock Block Diagram
SCALE
(divide by 2
n,
n = 0-5,7)
MUX
CLK_EXT
CLK_24MHz
CPUCLK
SEL
CLK_CPU
Doubler CLK_HS
LP OSC
32-KHz
CLK_32KHz
XTAL OSC
1-24MHz
CY7C601xx only
MUX
Crystal Oscillator Disabled
XOSC
SEL
EN
CLK_EXTEFTB
P0.0
CLKIN
P0.1
CLKOUT
CY7C601xx
only
Table 12-2. CPU Clock Configuration (CPUCLKCR) [0x30] [R/W]
Bit # 7 6 5 4 3 2 1 0
Field Reserved CPUCLK Select
Read/Write R/W
Default 0 0 0 0 0 0 0 0
Bit [7:1]: Reserved
Bit 0: CPU CLK Select
0 = Internal 24 MHz Oscillator
1 = External oscillator source
Note The CPU speed selection is configured using the OSC_CR0 Register (Table 12-3).
Table 12-3. OSC Control 0 (OSC_CR0) [0x1E0] [R/W]
Bit # 7 6 5 4 3 2 1 0
Field Reserved No Buzz Sleep Timer [1:0] CPU Speed [2:0]
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