EZ-USB Datasheet, PDF (164/334 Pages) Cypress Semiconductor – The EZ-USB USB Integrated Circuit

9 EZ-USB Interrupts
9.1 Introduction
The EZ-USB enhanced 8051 responds to the interrupts shown in Table 9-1. Interrupt
sources that are not present in the standard 8051 are shown as checked in the “New” col-
umn. The three interrupts used by the EZ-USB core are shown in bold type.
Table 9-1. EZ-USB Interrupts
New 8051 Interrupt (IRQ name)
Source
Vector (hex) Natural Priority
IE0
INT0# Pin
03
1
TF0
Timer 0 Overflow
0B
2
IE1
INT1# Pin
13
3
TF1
Timer 1 Overflow
1B
4
RI_0 & TI_0
UART0 Rx & Tx
23
5
P TF2
Timer 2 Overflow
2B
6
P Resume (PFI)
WAKEUP# Pin or USB Core
33
0
P RI_1 & TI_1
UART1 Rx & Tx
3B
7
P USB (INT2)
USB Core
43
8
P I²C (INT3)
USB Core
4B
9
P IE4
IN4 Pin
53
10
P IE5
INT5# Pin
5B
11
P IE6
INT6 Pin
63
12
The Natural Priority column in Table 9-1 shows the 8051 interrupt priorities. As
explained in Appendix C, the 8051 can assign each interrupt to a high or low priority
group. The 8051 resolves priorities within the groups using the natural priorities.
9.2 USB Core Interrupts
The EZ-USB core provides three interrupt request types, which are described in the fol-
lowing sections:
Wakeup - After the EZ-USB chip detects USB suspend and the 8051 has entered
its idle state, the EZ-USB core responds to an external signal on its
WAKEUP# pin or resumption of USB bus activity by re-starting the EZ-
USB oscillator and resuming 8051 operation.
EZ-USB TRM v1.9
Chapter 9. EZ-USB Interrupts
Page 9-1