AN2131QC Cypress Semiconductor Corp, AN2131QC Datasheet - Page 24

• Manufacturer Part Number: AN2131QC
• Description: IC MCU 8051 8K RAM 24MHZ 80BQFP
• Manufacturer: Cypress Semiconductor Corp
• Series: EZ-USB®r

Specifications of AN2131QC

• Applications: USB Microcontroller
• Core Processor: 8051
• Program Memory Type: ROMless
• Controller Series: AN213x
• Ram Size: 8K x 8
• Interface: I²C, USB
• Number Of I /o: 24
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 80-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1307

USB defines four transfer types. These match the requirements of different data types
delivered over the bus. (Section 1.13, "EZ-USB Endpoints" explains how the EZ-USB
family supports the four transfer types.)
1.8.1 Bulk Transfers
Bulk data is bursty, traveling in packets of 8, 16, 32, or 64 bytes. Bulk data has guaranteed
accuracy, due to an automatic re-try mechanism for erroneous data. The host schedules
bulk packets when there is available bus time. Bulk transfers are typically used for printer,
scanner, or modem data. Bulk data has built-in flow control provided by handshake pack-
ets.
1.8.2 Interrupt Transfers
Interrupt data is like bulk data, but exists only for IN endpoints in the “Universal Serial
Bus Specification Version 1.1.” Interrupt data can have packet sizes of 1-64 bytes. Inter-
rupt endpoints have an associated polling interval that ensures that they will be pinged
(will receive an IN token) by the host on a regular basis.
EZ-USB TRM v1.9
1.8
Token Packet
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Figure 1-4. Two Bulk Transfers, IN and OUT
Token Packet
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Figure 1-5. An Interrupt Transfer
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Chapter 1. Introducing EZ-USB
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