AN2131SC Cypress Semiconductor Corp, AN2131SC Datasheet - Page 49

• Manufacturer Part Number: AN2131SC
• Description: IC MCU 8051 8K RAM 24MHZ 44QFP
• Manufacturer: Cypress Semiconductor Corp
• Series: EZ-USB®r

Specifications of AN2131SC

• 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: 16
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 44-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1306; AN2131SC

The SFRs associated with 8051 ports 0-3 are not implemented in EZ-USB. These SFR
addresses include P0 (0x80), P1 (0x90), P2 (0xA0), and P3 (0xB0). Because P2 is not
implemented, the MOVX@R0/R1 instruction takes the upper address byte from an added
Special Function Register (SFR) at location 0x92. This register is called “MPAGE” in the
Appendices.
All standard 8051 interrupts are supported in the enhanced 8051 core. Table 2-1 shows
the existing and added 8051 interrupts, and indicates how the added ones are used.
The EZ-USB chip uses 8051 INT2 for 21 different USB interrupts: 16 bulk endpoints plus
SOF, Suspend, SETUP Data, SETUP Token, and USB Bus Reset. To help the 8051 deter-
mine which interrupt is active, the EZ-USB core provides a feature called Autovectoring.
The core inserts an address byte into the low byte of the 3-byte jump instruction found at
the 8051 INT2 vector address. This second level of vectoring automatically transfers con-
trol to the appropriate USB ISR. The Autovector mechanism, as well as the EZ-USB
interrupt system is the subject of Chapter 9, "EZ-USB Interrupts."
Page 2-4
2.7
•
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An output enable bit that causes the IO pin to be driven from the output latch.
An alternate function bit that determines whether the pin is general IO or a special
8051 or EZ-USB function.
Interrupts
INT0
INT1
Timer 0
Timer 1
Tx0 & Rx0
Standard 8051
Interrupts
Table 2-1. EZ-USB Interrupts
Enhanced 8051
INT2
INT3
INT4
INT5
INT6
PF1
Tx1 & Rx1
Timer 2
Chapter 2. EZ-USB CPU
Interrupts
Device Pin INT0#
Device Pin INT1#
Internal, Timer 0
Internal, Timer 1
Internal, UART0
Internal, USB
Internal, I
Device Pin, PB4/INT4
Device Pin, PB5/INT5#
Device Pin, PB6/INT6
Device Pin, USB WAKEUP#
Internal, UART1
Internal, Timer 2
2
Used As
C Controller
EZ-USB TRM v1.9