Themis CoolShell 3U, Руководство по установке, Страница: 29 / 158

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Themis Computer
Preface
A mixture of SMBus (BMC and PCH), I2C bus, and PMBus technology reside
within the CoolShell 3U.
Table 1 below shows the key differences between the bus
architectures found in the CoolShell 3U.
Table 1. System Bus Comparison
Specification
I
2
C
SMBus
PMBus
High
Power
Low
Power
Signaling
Packet Error Checking
(optional)
—
SMBALERT
(Optional)
—
Block Size Limit — 32 bytes 255 bytes
Timing
Data Rate
(Standard Mode)
100kbps
Data Rate
(Fast Mode)
400kbps — — 400kbps
Data Rate
(Fast Mode Plus)
1Mbps — — —
Data Rate
(High Speed Mode)
3.4Mbps — — —
Clock Speed 0Hz to 3.4Hz 10kHz to 100kHz 10kHz to 400kHz
Bus Timeout — 25ms to 35ms
Bus Master Request Delay
(Min)
— 50µs
SCL Hold Time
(Max)
— 2ms
Data Hold Time
(Min)
— 300ns