Rainbow Electronics LM87 - Manual (Page 24)

Functional Description
(Continued)
13.0 REGISTERS AND RAM
13.1 Address Pointer Register
The main register is the Address Pointer Register. The bit
designations are as follows:
Bit Name Read/Write Description
7-0 Address Pointer Write Address of RAM and Registers. See the tables below for detail.
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Address Pointer (Power On default 00h)
A7 A6 A5 A4 A3 A2 A1 A0
13.2 Address Pointer Index (A7–A0)
Registers and RAM
A6–A0 in
Hex
Power On Value of
Registers:
Notes
< 7:0 > in Binary
Internal Temp. Hardware
High Limit
13h 0100 0110 70 ˚C Default - < 7:0 > =0100 0110 - User
adjustable. Lockable by setting bit 1 of
register 4Ah.
External Temp. Hardware
High Limit
14h 0101 0101 85 ˚C Default - < 7:0 > =0101 0101 - User
adjustable. Lockable by setting bit 2 of
register 4Ah.
Test Register 15h 0000 0000 Always set to 00h
Channel Mode Register 16h 0000 0000
Internal Temp. Hardware
High Limit
17h 0100 0110 70 ˚C Default - < 7:0 > =0100 0110 - User
adjustable
External Temp. Hardware
High Limit
18h 0101 0101 85 ˚C Default - < 7:0 > =0101 0101 - User
adjustable
Value RAM 19h–3Dh See Section 13.18 for details. Address 19h
default=1111 1111
Company ID 3Eh 0000 0010 This designates the National Semiconductor
LM87.
Revision 3Fh 0000 0110 Revisions of this device will start with 1 and
increment by one.
Configuration Register 1 40h 0000 1000
Interrupt Status Register 1 41h 0000 0000
Interrupt Status Register 2 42h 0000 0000
Interrupt Mask Register 1 43h 0000 0000
Interrupt Mask Register 2 44h 0000 0000
CI Clear Register 46h 0000 0000
VID0-3/Fan Divisor 47h < 7:4 > = 0101;
Register < 3:0 > = VID3–VID0
VID4 Register 49h < 7:1 > =1000 000;
< 0 > =VID4
Configuration Register 2 4Ah 0000 0000
Interrupt Status Register 1
Mirror
4Ch 0000 0000
Interrupt Status Register 2
Mirror
4Dh 0000 0000
SMBALERT# Enable 80h 0010 0000
LM87
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