101-0402 Rabbit Semiconductor, 101-0402 Datasheet - Page 71

• Manufacturer Part Number: 101-0402
• Description: KIT DEV TCP/IP 2000 INTL
• Manufacturer: Rabbit Semiconductor
• Series: RabbitCore 2000r
• Type: MPU Moduler

Specifications of 101-0402

• Contents: RabbitCore Module, Dev. Board, Cable and Dynamic C® CD-Rom
• For Use With/related Products: RCM2000, RCM2010, RCM2020
• Lead Free Status / RoHS Status: Vendor undefined / Vendor undefined

Transistors Q5 and Q6 are of opposite polarity so that a rail-to-rail voltage can be passed.
When the /CS1 voltage is low, Q5 will conduct. When the /CS1 voltage is high, Q6 will
conduct. It takes time for the transistors to turn on, creating a propagation delay. This
delay is typically very small, about 10 ns to 15 ns.
The signal that turns the transistors on is a high on the processor’s reset line, /RES. When
the TCP/IP Development Board is not in reset, the reset line will be high, turning on n-
channel Q5 and Q7. Q7 is a simple inverter needed to turn on Q6, a p-channel MOSFET.
When a reset occurs, the /RES line will go low. This will cause C14 to discharge through
R32 and R34. This small delay (about 160 µs) ensures that there is adequate time for the
processor to write any last byte pending to the SRAM before the processor puts itself into
a reset state. When coming out of reset, CS will be enabled very quickly because D1 con-
ducts to charge capacitor C14.
Getting Started
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