UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
61 of 362
NXP Semiconductors
UM10208
Chapter 7: LPC2800 CGU
Table 48.
Status Register (HPSTAT - 0x8000 4CC0)
Bit
Symbol
Description
Reset
value
0
HPLOCK
Lock Status.
A 1 in this bit indicates that the HS PLL has achieved
synchronization lock, so that its output can be used for clocking. At
slow input frequencies this bit is not reliable: a timeout of 500 uS
should be applied to waiting for it to be set.
0
1
HPFREE
Free Running Status.
This bit is 1 if the HS PLL is in free-running
mode.
0
31:2
-
Reserved. The value read from a reserved bit is not defined.
-
Table 49.
Rate Change Request Register (HPREQ - 0x8000 4CC8)
Bit
Symbol
Description
Reset
value
0
HPMREQ
After dynamically changing the MDEC, SELI, SELR, and/or SELP
registers, write a 1 to this bit, wait for the MACK bit in HPACK to be set,
then clear this bit, then wait for MACK to be 0.
0
1
HPNREQ
After dynamically changing the NDEC register, write a 1 to this bit, wait
for the NACK bit in HPACK to be set, then clear this bit, then wait for
NACK to be 0.
0
2
HPPREQ
After dynamically changing the PDEC register, write a 1 to this bit, wait
for the PACK bit in HPACK to be set, then clear this bit, then wait for
PACK to be 0.
0
31:3
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
-
Table 50.
Rate Change Acknowledge Register (HPACK - 0x8000 4CC4)
Bit
Symbol
Description
Reset
value
0
HPMACK
After dynamically changing the MDEC, SELI, SELR, and/or SELP
registers, write a 1 to MREQ in HPREQ, wait for this bit to be set, then
clear MREQ, then wait for this bit to be 0.
0
1
HPNACK
After dynamically changing the NDEC register, write a 1 to NREQ in
HPREQ, wait for this bit to be set, then clear NREQ, then wait for this
bit to be 0.
0
2
HPPACK
After dynamically changing the PDEC register, write a 1 to PREQ in
HPREQ, wait for this bit to be set, then clear PREQ, then wait for this
bit to be 0.
0
31:3
-
Reserved. The value read from a reserved bit is not defined.
-
Table 51.
R Bandwidth Register (HPSELR - 0x8000 4CD8)
Bit
Symbol
Description
Reset
value
3:0
SELR
The value to be written to this field depends on the multiplication factor,
and can be determined as described in
0
31:4
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
-