Table 17-12. Uir Register; Table 17-13. Uir Fields; Interrupt Register For Common Usb Interrupts (Uir) - Sharp LH79524 User Manual

Universal Serial Bus Device

17.2.2.5 Interrupt Register for common USB interrupts (UIR)

UIR is a read-only register that indicates which USB interrupts are currently active. All
active interrupts will be cleared when this register is read.
BIT
FIELD
RESET
RW
BIT
FIELD
RESET
TYPE
ADDR
BITS
31:4
3
2
1
0
17-14
31 30 29 28
0 0 0 0
RO RO RO RO RO
15 14 13 12
0 0 0 0
RO RO RO RO RO
NAME
/// Reserved Reading returns 0. Write the reset value.
SOF Interrupt The USB block programs this bit to 1 at the start of each frame.
SOF
1 = Start of Frame detected
0 = Interrupt cleared
USB RESET Interrupt The USB block programs this bit to 1 when it receives
RESET signalling from the USB Host. Software clears this interrupt by reading
this register.
URINT
1 = USB RESET Interrupt set
0 = Interrupt cleared
RESUME Interrupt The USB block programs this bit to 1 when it receives
RESUME signalling while in SUSPEND mode from the USB Host. If the
RESUME is due to a USB RESET, the CPU is first interrupted with a RESUME
interrupt. Once the clocks resume and the SUSPEND condition persists for 3
RESINT
ms, USB RESET Interrupt will be asserted. Software clears this interrupt by
reading this register.
1 = RESUME Interrupt set
0 = Interrupt cleared
SUSPEND Interrupt The USB block programs this bit to 1 when it receives
SUSPEND signaling from the USB Host. This bit is set whenever there is no
activity for 3 ms on the bus. Thus, if the CPU does not stop the clock after the
first SUSPEND Interrupt, it will continue to be interrupted every 3 ms as long as
SUSINT
there is no activity on the USB bus. This interrupt is disabled by default. Soft-
ware clears this interrupt by reading this register.
1 = SUSPEND Interrupt set
0 = Interrupt cleared

Table 17-12. UIR Register

27 26 25 24 23
///
0 0 0 0 0
RO RO RO RO
11 10 9 8 7
///
0 0 0 0 0
RO RO RO RO
0xFFFF5000 + 0x018

Table 17-13. UIR Fields

FUNCTION
Version 1.0
LH79524/LH79525 User's Guide
22 21 20 19 18
0 0 0 0 0
RO RO RO RO RO
6 5 4 3 2
0 0 0 0 0
RO RO RO RO RO
17 16
0 0
RO RO
1 0
0 0
RO RO