pc87591l National Semiconductor Corporation, pc87591l Datasheet - Page 246

• Manufacturer Part Number: pc87591l
• Description: Lpc Mobile Embedded Controllers
• Manufacturer: National Semiconductor Corporation

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Embedded Controller Modules
HFCGI Low Value Register (HFCGIL)
The HFCGIL register contains the lower eight bits of the frequency multiplier I value. Data written to the register is stored in
the setup buffer. Reading the register returns the value of its first 8 bits. (IVLID bit in HFCGCTRL1 register indicates if the
data is valid.)
Location: 00 FFA8
Type: R/W
HFCGI High Value Register (HFCGIH)
The HFCGIH register is a byte-wide, read/write register containing the upper six bits of the frequency multiplier I value. Data
written to the register is stored in the setup buffer. Reading the register returns the HFCGIH value of the currently set fre-
quency.
Location: 00 FFAA
Type: R/W
HFCG Pre-Scaler Register (HFCGP)
The HFCGP register is a byte-wide, read/write register. It allows the core clock to be derived from the 96 MHz clock.
On reset HFCGP is initialized to 17
Location: 00 FFAC
Type: R/W
Bit
Name
Bit
Name
Bit
Name
Reset
5-0
7-6
Bit
Bit
7-0
4-0
7-5
Bit
HFCGI13-8. Contains the upper six bits of the I value.
Reserved.
HFCGI7-0. Contains the lower eight bits of the I value.
HFCGP4-0 (Pre-Scaler Divider Value). The divider of OSCCLK is the number defined by HFCGP(4-0) + 1,
e.g., a value of 00
Results are undefined when the pre-scaler holds a value that yields a core domain clock frequency higher than
20 MHz or lower than 3 MHz.
The pre-scaler is set according to the value held in HFCGP register when LOAD96 bit or FAST96 bit is set (1).
Reading HFCGP register returns the last value written to it.
Reserved.
16
16
16
7
7
7
0
Reserved
16
Reserved
results in a divide by 1; a value of 1F
6
6
6
0
16
.
(Continued)
5
5
5
0
246
Description
Description
Description
4
4
4
1
HFCGI7-0
16
results in a divide by 32.
3
3
3
0
HFCGI13-8
HFCGP4-0
2
2
1
2
1
1
1
1
Revision 1.07
0
0
0
1