MIC2593 Datasheet, PDF (15/26 Pages) STMicroelectronics – Dual-Slot PCI Hot Plug Controller

MIC2593
Micrel
dure may be used. To perform a Receive_Byte operation, the
host sends an address byte to select the slave MIC2593, with
the R/W bit set to the high (read) state, and then retrieves the
data byte. Figures 9 through 11 show the formats for these
data read and data write procedures.
The Command Register is eight bits (one byte) wide. This
byte carries the address of the MIC2593’s register to be
operated upon. The command byte values corresponding to
the various MIC2593 register addresses are shown in Table
4. Command byte values other than 0000 0XXX_b = 00_h - 07_h
are reserved and should not be used.
MIC2593 Register Set and Programmer’s Model
Target Register
Inputs
MIC2593 Slave Address
A2 A1 A0
Binary
Hex
0
0
0
1000 000_b
80_h
0
0
1
1000 001_b
82_h
0
1
0
1000 010_b
84_h
0
1
1
1000 011_b
86_h
1
0
0
1000 100_b
88_h
1
0
1
1000 101_b
8A_h
1
1
0
1000 110_b
8C_h
1
1
1
1000 111_b
8E_h
Table 3. MIC2593 SMBus Addressing
Command Byte Value
Power-On
Default
Label
Description
Read
Write
RESERVED
RESERVED
CNTRLA
CNTRLB
STATA
STATB
CS
Reserved
Do not Use
00_h
Do not Use
01_h
Control Register Slot A
02_h
Control Register Slot B
03_h
Slot A Status
04_h
Slot B Status
05_h
Common Status Register
06_h
Reserved / Do Not Use
07_h - FF_h
Table 4. MIC2593 Register Addresses
n/a
n/a
02_h
03_h
04_h
05_h
06_h
07_h - FF_h
n/a
n/a
00_h
00_h
00_h
00_h
xxxx 0000_b
Undefined
MIC2593 Slave Address
Command Byte to MIC2593 Data Byte to MIC2593
DATA S 1 0 0 1 A2 A1 A0 0 A 0 0 0 0 0 0 X X A D7 D6 D5 D4 D3 D2 D1 D0 A P
START
R/W = WRITE
ACKNOWLEDGE
ACKNOWLEDGE
ACKNOWLEDGE
STOP
CLK
Master to slave transfer,
i.e., DATA driven by master.
Slave to master transfer,
i.e., DATA driven by slave.
Figure 9. WRITE_BYTE Protocol
MIC2593 Slave Address
Command Byte to MIC2593
MIC2593 Slave Address Data Read From MIC2593
DATA S 1 0 0 1 A2 A1 A0 0 A 0 0 0 0 0 0 X X A S 1 0 0 1 A2 A1 A0 1 A D7 D6 D5 D4 D3 D2 D1 D0 /A P
START
R/W = WRITE
ACKNOWLEDGE
ACKNOWLEDGE
START
R/W = READ
ACKNOWLEDGE NOT ACKNOWLEDGE
STOP
CLK
Master to slave transfer,
i.e., DATA driven by master.
Slave to master transfer,
i.e., DATA driven by slave.
Figure 10. READ_BYTE Protocol
MIC2593 Slave Address
Byte Read from MIC2593
DATA S 1 0 0 1 A2 A1 A0 1 A D7 D6 D5 D4 D3 D2 D1 D0 /A P
START
R/W = READ
ACKNOWLEDGE NOT ACKNOWLEDGE
STOP
CLK
Master to slave transfer,
i.e., DATA driven by master.
Slave to master transfer,
i.e., DATA driven by slave.
Figure 11. RECEIVE_BYTE Protocol
April 2004
15
M9999-042204