ICS9248-66 Datasheet, PDF (3/11 Pages) Integrated Circuit Systems – Frequency Timing Generator for PENTIUM II Systems

ICS9248-66
Advance Information
Frequency Select:
SEL
133/100-
#
0
0
SEL1
0
0
SEL0
0
1
CPU
MHz
Hi-Z
N/A
CPU/2
MHz
Hi-Z
N/A
3V66
MHz
Hi-Z
N/A
PCI
MHz
Hi-Z
N/A
48
MHz
Hi-Z
N/A
REF
MHz
Hi-Z
N/A
IOAPIC
MHz
Hi-Z
N/A
0
1
0
100
50
66.6
33.3 Hi-Z 14.318 16.67
0
1
1
100
50
66.6
33.3
48 14.318 16.67
1
0
0
TCLK/2 TCLK/4
TCLK/4
TCLK/8
TCLK/-
2
TCLK
TCLK/16
1
0
1
N/A
N/A
N/A
N/A N/A N/A
N/A
1
1
0 133.3 66.6
66.6
33.3 Hi-Z 14.318 16.67
1
1
1 133.3 66.6
66.6
33.3
48 14.318 16.67
Comments
Tri-state
Reserved
48MHz PLL
disabled
Test mode (1)
Reserved
Note:
1. TCLK is a test clock driven on the x1 input during test mode.
ICS9248-66 Power Management Features:
CPU_STOP#
X
PD# PCI_STOP# CPUCLK CPU/2 IOAPIC 3V66
0
X
LOW LOW LOW LOW
PCI
PCI_F
REF.
48MHz
Osc
LOW LOW LOW OFF
VCOs
OFF
0
1
0
LOW
ON
ON LOW LOW ON
ON
ON
ON
0
1
1
LOW
ON
ON LOW ON
ON
ON
ON
ON
1
1
0
ON
ON
ON
ON LOW ON ON ON ON
1
1
1
ON
ON
ON
ON ON ON ON ON ON
Note:
1. LOW means outputs held static LOW as per latency requirement next page.
2. On means active.
3. PD# pulled Low, impacts all outputs including REF and 48 MHz outputs.
4. All 3V66 as well as all CPLU clocks should stop cleanly when CPU_STOP# is pulled LOW.
5. CPU/2, IOAPIC, REF, 48 MHz signals are not controlled by the CPU_STOP# functionality and are enabled all in all conditions
except PD# = LOW
3