cs5535 National Semiconductor Corporation, cs5535 Datasheet - Page 542

• Manufacturer Part Number: cs5535
• Description: Geode Cs5535 Companion Multi-function South Bridge
• Manufacturer: National Semiconductor Corporation

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Electrical Specifications
6.3.7
The signals detailed in this sub-section use an “SMB”
buffer type. For a detailed explanation of buffer types, see
Table 2-4 "Buffer Type Characteristics" on page 28.
The SMB utilizes a two-wire asynchronous protocol. Mas-
ter and slave devices are connected open-drain with an
external pull-up resistor. The SMB_CLK is not a free run-
ning fixed frequency signal, but rather a cooperatively gen-
erated signal with a minimum low time of 4.7 µs, minimum
high time of 4.0 µs, and 100 kHz frequency limit. The mini-
mum frequency is 10 kHz. The SMB_DATA signal is also
Signal
Bidirectional
SMB_CLK (GPIO14),
SMB_DATA (GPIO15)
System Management Bus (SMB) Signals
Parameter
Async Output or Level
Async Input
(Continued)
Table 6-15. SMB Timing Parameters
Min
NA
NA
542
cooperatively driven. Communication on the SMB is via rel-
ative manipulation of these two signals. The SMB Control-
ler and I/O cell incorporated within the CS5535 fully meets
the requirements of the SMB specification version 2.0.
In this subsection, unless otherwise noted:
• All timing specifications are specified under the oper-
ating conditions listed in Table 6-3 on page 526 (i.e.,
V
T
Max
CORE
CASE
NA
NA
= All).
and V
Units
ns
ns
CORE_VSB
Comment/Condition
No clock reference.
No clock reference.
= All; V
IO
and V
IO_VSB
= All;
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