Rainbow Electronics AT89C5131 User Manual
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AT89C5131
4136A–USB–03/03
Table 82. Priority Levels
USB Interrupt Control System
As shown in Figure 64, many events can produce a USB interrupt:
•
TXCMPL: Transmitted In Data (see Table 89 on page 138). This bit is set by 
hardware when the Host accept a In packet.
•
RXOUTB0: Received Out Data Bank 0 (see Table 89 on page 138). This bit is set 
by hardware when an Out packet is accepted by the endpoint and stored in bank 0.
•
RXOUTB1: Received Out Data Bank 1 (only for Ping-pong endpoints) (see Table 89 
on page 138). This bit is set by hardware when an Out packet is accepted by the 
endpoint and stored in bank 1.
•
RXSETUP: Received Setup (see Table 89 on page 138). This bit is set by hardware 
when an SETUP packet is accepted by the endpoint.
•
STLCRC: STALLED (only for Control, Bulk and Interrupt endpoints) (see Table 89 
on page 138). This bit is set by hardware when a STALL handshake has been sent 
as requested by STALLRQ, and is reset by hardware when a SETUP packet is 
received. 
•
SOFINT: Start of Frame Interrupt (See “USBIEN Register USBIEN (S:BEh) USB 
Global Interrupt Enable Register” on page 135). This bit is set by hardware when a 
USB Start of Frame packet has been received.
•
WUPCPU: Wake-Up CPU Interrupt (See “USBIEN Register USBIEN (S:BEh) USB 
Global Interrupt Enable Register” on page 135). This bit is set by hardware when a 
USB resume is detected on the USB bus, after a SUSPEND state.
•
SPINT: Suspend Interrupt (See “USBIEN Register USBIEN (S:BEh) USB Global 
Interrupt Enable Register” on page 135). This bit is set by hardware when a USB 
suspend is detected on the USB bus.
IPHUSB
IPLUSB
USB Priority Level
0
0
0 Lowest
0
1
1
1
0
2
1
1
3
Highest
