EZ-USB TRM v1.9 Chapter 4. EZ-USB CPU Page 4-1
4 EZ-USB Input/Output
The EZ-USB chip provides two input-output systems:
• A set of programmable IO pins
• A programmable I
2
C Controller
This chapter begins with a description of the programmable IO pins, and shows how they
are shared by a variety of 8051 and EZ-USB alternate functions such as UART, timer and
interrupt signals.
The I
2
C controller uses the SCL and SDA pins, and performs two functions:
• General-purpose 8051 use
• Boot loading from an EEPROM
This chapter describes both the programming information for the 8051 I
2
C interface, and
the operating details of the I
2
C boot loader. The role of the boot loader is described in
Chapter 5, "EZ-USB Enumeration and ReNumeration."
4.1 Introduction
Note
2.2-KB to 4.7-KB pullups are required on the SDA and SCL lines.
Comments to this Manuals