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Commit | Line | Data |
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1da177e4 LT |
1 | November 23, 2004 |
2 | ||
3 | The following specification describes the SMSC LPC47B397-NC sensor chip | |
4 | (for which there is no public datasheet available). This document was | |
5 | provided by Craig Kelly (In-Store Broadcast Network) and edited/corrected | |
6 | by Mark M. Hoffman <mhoffman@lightlink.com>. | |
7 | ||
8 | * * * * * | |
9 | ||
10 | Methods for detecting the HP SIO and reading the thermal data on a dc7100. | |
11 | ||
12 | The thermal information on the dc7100 is contained in the SIO Hardware Monitor | |
13 | (HWM). The information is accessed through an index/data pair. The index/data | |
14 | pair is located at the HWM Base Address + 0 and the HWM Base Address + 1. The | |
15 | HWM Base address can be obtained from Logical Device 8, registers 0x60 (MSB) | |
16 | and 0x61 (LSB). Currently we are using 0x480 for the HWM Base Address and | |
17 | 0x480 and 0x481 for the index/data pair. | |
18 | ||
19 | Reading temperature information. | |
20 | The temperature information is located in the following registers: | |
21 | Temp1 0x25 (Currently, this reflects the CPU temp on all systems). | |
22 | Temp2 0x26 | |
23 | Temp3 0x27 | |
24 | Temp4 0x80 | |
25 | ||
26 | Programming Example | |
27 | The following is an example of how to read the HWM temperature registers: | |
28 | MOV DX,480H | |
29 | MOV AX,25H | |
30 | OUT DX,AL | |
31 | MOV DX,481H | |
32 | IN AL,DX | |
33 | ||
34 | AL contains the data in hex, the temperature in Celsius is the decimal | |
35 | equivalent. | |
36 | ||
37 | Ex: If AL contains 0x2A, the temperature is 42 degrees C. | |
38 | ||
39 | Reading tach information. | |
40 | The fan speed information is located in the following registers: | |
41 | LSB MSB | |
42 | Tach1 0x28 0x29 (Currently, this reflects the CPU | |
43 | fan speed on all systems). | |
44 | Tach2 0x2A 0x2B | |
45 | Tach3 0x2C 0x2D | |
46 | Tach4 0x2E 0x2F | |
47 | ||
48 | Important!!! | |
49 | Reading the tach LSB locks the tach MSB. | |
50 | The LSB Must be read first. | |
51 | ||
52 | How to convert the tach reading to RPM. | |
53 | The tach reading (TCount) is given by: (Tach MSB * 256) + (Tach LSB) | |
54 | The SIO counts the number of 90kHz (11.111us) pulses per revolution. | |
55 | RPM = 60/(TCount * 11.111us) | |
56 | ||
57 | Example: | |
58 | Reg 0x28 = 0x9B | |
59 | Reg 0x29 = 0x08 | |
60 | ||
61 | TCount = 0x89B = 2203 | |
62 | ||
63 | RPM = 60 / (2203 * 11.11111 E-6) = 2451 RPM | |
64 | ||
65 | Obtaining the SIO version. | |
66 | ||
67 | CONFIGURATION SEQUENCE | |
68 | To program the configuration registers, the following sequence must be followed: | |
69 | 1. Enter Configuration Mode | |
70 | 2. Configure the Configuration Registers | |
71 | 3. Exit Configuration Mode. | |
72 | ||
73 | Enter Configuration Mode | |
74 | To place the chip into the Configuration State The config key (0x55) is written | |
75 | to the CONFIG PORT (0x2E). | |
76 | ||
77 | Configuration Mode | |
78 | In configuration mode, the INDEX PORT is located at the CONFIG PORT address and | |
79 | the DATA PORT is at INDEX PORT address + 1. | |
80 | ||
81 | The desired configuration registers are accessed in two steps: | |
82 | a. Write the index of the Logical Device Number Configuration Register | |
83 | (i.e., 0x07) to the INDEX PORT and then write the number of the | |
84 | desired logical device to the DATA PORT. | |
85 | ||
86 | b. Write the address of the desired configuration register within the | |
87 | logical device to the INDEX PORT and then write or read the config- | |
88 | uration register through the DATA PORT. | |
89 | ||
90 | Note: If accessing the Global Configuration Registers, step (a) is not required. | |
91 | ||
92 | Exit Configuration Mode | |
93 | To exit the Configuration State the write 0xAA to the CONFIG PORT (0x2E). | |
94 | The chip returns to the RUN State. (This is important). | |
95 | ||
96 | Programming Example | |
97 | The following is an example of how to read the SIO Device ID located at 0x20 | |
98 | ||
99 | ; ENTER CONFIGURATION MODE | |
100 | MOV DX,02EH | |
101 | MOV AX,055H | |
102 | OUT DX,AL | |
103 | ; GLOBAL CONFIGURATION REGISTER | |
104 | MOV DX,02EH | |
105 | MOV AL,20H | |
106 | OUT DX,AL | |
107 | ; READ THE DATA | |
108 | MOV DX,02FH | |
109 | IN AL,DX | |
110 | ; EXIT CONFIGURATION MODE | |
111 | MOV DX,02EH | |
112 | MOV AX,0AAH | |
113 | OUT DX,AL | |
114 | ||
115 | The registers of interest for identifying the SIO on the dc7100 are Device ID | |
116 | (0x20) and Device Rev (0x21). | |
117 | ||
118 | The Device ID will read 0X6F | |
119 | The Device Rev currently reads 0x01 | |
120 | ||
121 | Obtaining the HWM Base Address. | |
122 | The following is an example of how to read the HWM Base Address located in | |
123 | Logical Device 8. | |
124 | ||
125 | ; ENTER CONFIGURATION MODE | |
126 | MOV DX,02EH | |
127 | MOV AX,055H | |
128 | OUT DX,AL | |
129 | ; CONFIGURE REGISTER CRE0, | |
130 | ; LOGICAL DEVICE 8 | |
131 | MOV DX,02EH | |
132 | MOV AL,07H | |
133 | OUT DX,AL ;Point to LD# Config Reg | |
134 | MOV DX,02FH | |
135 | MOV AL, 08H | |
136 | OUT DX,AL;Point to Logical Device 8 | |
137 | ; | |
138 | MOV DX,02EH | |
139 | MOV AL,60H | |
140 | OUT DX,AL ; Point to HWM Base Addr MSB | |
141 | MOV DX,02FH | |
142 | IN AL,DX ; Get MSB of HWM Base Addr | |
143 | ; EXIT CONFIGURATION MODE | |
144 | MOV DX,02EH | |
145 | MOV AX,0AAH | |
146 | OUT DX,AL |