ML410 Embedded Development Platform
www.xilinx.com
69
UG085 (v1.7.2) December 11, 2008
Detailed Description
R
IIC/SMBus Interface
Introduction to IIC/SMBus
The Inter Integrated Circuit (IIC) bus provides the connection from the CPU to peripherals.
It is a serial bus with a data signal, SDA, and a clock signal, SCL, both of which are
bidirectional. The IIC/SMBus interface serves as an interface to one master device and
multiple slave devices. The interface operates in the range of 100 kHz to 400 kHz.
The SMBus also provides connectivity from the CPU to peripherals. The SMBus is also a
two wire serial bus through which simple power related devices can communicate with
the rest of the system. SMBus uses IIC as its backbone. EDK provides IP that integrates the
IIC interface with a microprocessor system. See the EDK
Processor IP User Guide
[Ref 2]
for
more details.
IIC/SMBus Signaling
The IIC bus data and clock signals operate as open-drain. By default, these signals are
pulled High to 5V, although some devices support lower voltages. Either the master device
or a slave device can drive either of the signals Low to transmit data or clock signals.
ROM_A14
T16
5
ROM_A13
U16
4
ROM_A12
V16
12
ROM_A11
W16
1
ROM_A10
Y16
31
ROM_A9
R17
2
ROM_A8
T17
3
ROM_A7
U17
13
ROM_A6
V17
14
ROM_A5
W17
15
ROM_A4
Y17
16
ROM_A3
V18
17
ROM_A2
W18
18
ROM_A1
Y18
19
ROM_A0
V19
20
Table 2-34:
ALi Flash Memory Interface
(Cont’d)
Schematic Net
Name
Pin
(U15)
AM29F040B Pin
(U4)
Description
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