HighWire HW400c/2 User Reference Guide Rev 1.0
4.2.14 PLL Configuration Register B (PLLB)
ter
long with PLLA) can help software determine the CPU operating frequency, as
well a
Table 43. PLL Configuration Register B (PLLB) Addr 3
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
The PLL Configuration Register B (PLLB) is a Read-Only register. It contains the
settings for the System bus and Device bus (external) PLLs. Reading this regis
(a s the Device bus operating frequency.
Offset ess 0x1
Reserved SPLL1 ed Reserved DPLL1 DPLL0 Reserved SPLL2 Reserv
SPLL[1:0] = 00 is 100 MHz
is 133 MHz
c/2
PLL[1:0]
400c/2
System bus clock
= 01 System bus clock
= 10 System bus clock is 166 MHz (Default for HW400
standard version)
= 11 System bus clock is 200 MHz
D = 00
= 01
Device bus clock is 100 MHz
Device bus clock is 133 MHz (Default for HW
standard version)
Reserved
Reserved
= 10
= 11
October 10, 2006 Copyright 2006, SBE, Inc. Page 55