ICS94211 Datasheet, PDF (7/16 Pages) Integrated Circuit Systems – Programmable System Frequency Generator for PII/III™

ICS94211
Byte 7: Vendor ID and Revision ID Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
0 Vendor ID
0 Vendor ID
1 Vendor ID
X Revision ID
X Revision ID
X Revision ID
X Revision ID
X Revision ID
Byte 8: Byte Count and Read Back Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
0 Reserved
0 Reserved
0 Reserved
0 Reserved
1 Reserved
0 Reserved
0 Reserved
0 Reserved
Description
Byte 9: VCO Control Selection Bit &
Watchdog Timer Control Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
0 0=Hw/B0 freq / 1=B14&15 freq
0 WD Enable 0=disable / 1=enable
0 WD Status 0=normal / 1=alarm
0 WD Safe Frequency, Byte 0 bit 2
0 WD Safe Frequency, FS3
0 WD Safe Frequency, FS2
0 WD Safe Frequency, FS1
0 WD Safe Frequency, FS0
Note: FS values in bit [0:4] will correspond to Byte 0 FS
values. Default safe frequency is same as 00000 entry in
byte0.
Byte 11: VCO Frequency Control Register
Bit PWD
Description
Bit 7 X VCO Divider Bit0
Bit 6 X REF Divider Bit6
Bit 5 X REF Divider Bit5
Bit 4 X REF Divider Bit4
Bit 3 X REF Divider Bit3
Bit 2 X REF Divider Bit2
Bit 1 X REF Divider Bit1
Bit 0 X REF Divider Bit0
Note: The decimal representation of these 7 bits (Byte 11
[6:0]) + 2 is equal to the REF divider value .
Notes:
1. PWD = Power on Default
Byte 10: Watchdog Timer Count Register
Bit PWD
Description
Bit 7 0
Bit 6 0 The decimal representation of these
Bit 5 0 ^{8 bits correspond to 290ms or 1ms}
Bit 4
Bit 3
1
0
the watchdog timer will wait before
it goes to alarm mode and reset the
frequency to the safe setting. Default
Bit 2 0 _{at power up is 16X 290ms = 4.6}
Bit 1 0 seconds.
Bit 0 0
Byte 12: VCO Frequency Control Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
X VCO Divider Bit8
X VCO Divider Bit7
X VCO Divider Bit6
X VCO Divider Bit5
X VCO Divider Bit4
X VCO Divider Bit3
X VCO Divider Bit2
X VCO Divider Bit1
Note: The decimal representation of these 9 bits (Byte 12 bit
[7:0] & Byte 11 bit [7] ) + 8 is equal to the VCO divider value.
For example if VCO divider value of 36 is desired, user need
to program 36 - 8 = 28, namely, 0, 00011100 into byte 12 bit
& byte 11 bit 7.
7