Specifications

9 March 1999 – Subject To Change Functional Description 4–15
System Clocks
• Miscellaneous clocks — The miscellaneous clocks include those needed for
ISA and the combination controller. These clocks are provided by a crystal and a
frequency generator with fixed scaling.
Figure 4–7 AlphaPC 164LX System Clocks
21164
pc164lx.2
82378ZB
Bridge
pc164lx.22
14mhz_out
osc
37C935
Combination
pc164lx.25
sysclk
Oscillator
FM-05950.AI4
14.3-MHz
pc164lx.3
Microprocessor
irq_h<3:0>
clk_in_h
clk_in_l
21174
pc164lx.4
ISA
Slots
pc164lx.29
PCI
Slots
Controller
sys_clk_out1
DIMM0
DIMM1
DIMM2
DIMM3
dram_clkax2
pciclk_slot0
pciclk_sio
pciclk_slot1
pciclk_slot2
pciclk_slot3
J27 Jumpers
pciclk_arb
pciclk_ide
pc164lx.20-21
pc164lx.23
Microprocessor
Clock
Synthesizer
(MC12439)
dram_clkbx2
dram_clkcx2
dram_clkdx2
CY2308
PLL