CY2277A
Byte 1: CPU, 24/48 MHz Active/Inactive
Register (1 = Active, 0 = Inactive), Default = Active
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Pin #
23
22
--
N/A
38
39
41
42
Description
48/24 MHz (Active/Inactive)
48/24 MHz (Active/Inactive)
(Reserved) drive to ‘0’
Not Used, drive 0
CPUCLK3 (Active/Inactive)
CPUCLK2 (Active/Inactive)
CPUCLK1 (Active/Inactive)
CPUCLK0 (Active/Inactive)
Byte 2: PCI Active/Inactive
Register (1 = Active, 0 = Inactive), Default = Active
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
--
8
16
14
13
12
11
9
Pin #
Description
(Reserved) drive to ‘0’
PCICLK_F (Active/Inactive)
PCICLK5 (Active/Inactive)
PCICLK4 (Active/Inactive)
PCICLK3 (Active/Inactive)
PCICLK2 (Active/Inactive)
PCICLK1 (Active/Inactive)
PCICLK0 (Active/Inactive)
Byte 3: SDRAM Active/Inactive
Register (1 = Active, 0 = Inactive), Default = Active
Bit
Pin #
Description
SDRAM7 (Active/Inactive)
SDRAM6 (Active/Inactive)
SDRAM5 (Active/Inactive)
SDRAM4 (Active/Inactive)
SDRAM3 (Active/Inactive)
SDRAM2 (Active/Inactive)
SDRAM1 (Active/Inactive)
SDRAM0 (Active/Inactive)
Bit 7 26
Bit 6 27
Bit 5 29
Bit 4 30
Bit 3 32
Bit 2 33
Bit 1 35
Bit 0 36
Byte 4: SDRAM Active/Inactive
Register (1 = Active, 0 = Inactive), Default = Active
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Pin #
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Description
Not used, drive to ‘0’
Not used, drive to ‘0’
Not used, drive to ‘0’
Not used, drive to ‘0’
Not used, drive to ‘0’
Not used, drive to ‘0’
Not used, drive to ‘0’
Not used, drive to ‘0’
Byte 5: Peripheral Active/Inactive
Register (1 = Active, 0 = Inactive), Default = Active
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Pin #
--
--
--
45
--
--
1
2
Description
(Reserved) drive to ‘0’
(Reserved) drive to ‘0’
(Reserved) drive to ‘0’
IOAPIC (Active/Inactive)
(Reserved) drive to ‘0’
(Reserved) drive to ‘0’
REF1 (Active/Inactive)
REF0 (Active/Inactive)
Byte 6: Reserved, for future use
Rev 1.0, November 25, 2006
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