28 USB FUNCTION CONTROLLER (USB)
28-26
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
Detailed Description of Registers
28.6.2
MainIntStat (Main Interrupt Status)
Register name Address
Bit
Name
Setting
Init. R/W
Remarks
MainIntStat
(Main interrupt
status)
0x300c00
(8 bits)
D7
SIE_IntStat
1 SIE interrupts
0 None
0
R
D6
EPrIntStat
1 EPr interrupts
0 None
0
R
D5
DMA_IntStat
1 DMA interrupts
0 None
0
R
D4
FIFO_IntStat
1 FIFO interrupts
0 None
0
R
D3–2 –
–
–
–
0 when being read.
D1
EP0IntStat
1 EP0 interrupts
0 None
0
R
D0
RcvEP0SETUP
1 Receive EP0 SETUP
0 None
0
R(W)
This register displays causes of interrupt having occurred in the USB function controller. This register has the bit
indirectly showing causes of interrupt and the bit directly showing causes of interrupt.
The bit indirectly showing causes of interrupt can be traced to the bit directly showing causes of interrupt by read-
ing the relevant status registers. The bit showing causes of interrupt is read-only, and is automatically cleared by
clearing the bit directly showing causes of interrupt at the main source. The bits showing causes of interrupt are
writable, and the causes of interrupt can be cleared by setting the relevant bits to 1. When the corresponding bits are
enabled by the MainIntEnb register, setting the cause of interrupt to 1 asserts the #INT signal, and causes an inter-
ruption of the CPU. Clearing all relevant causes of interrupt negates the #INT signal.
D7
SIE_IntStat
Shows a cause of interrupt indirectly.
When the SIE_IntStat register has a cause of interrupt and the SIE_IntEnb register bit corresponding to
the cause of interrupt is enabled, this bit is set to 1. Reading this bit is valid during snooze as well.
D6
EPrIntStat
Shows a cause of interrupt indirectly.
When the EPrIntStat register has a cause of interrupt and the EPrIntEnb register bit corresponding to
the cause of interrupt is enabled, this bit is set to 1.
D5
DMA_IntStat
Shows a cause of interrupt indirectly.
When the DMA_IntStat register has a cause of interrupt and the DMA_IntEnb register bit correspond-
ing to the cause of interrupt is enabled, this bit is set to 1.
D4
FIFO_IntStat
Shows a cause of interrupt indirectly.
When the FIFO_IntStat register has a cause of interrupt and the FIFO_IntEnb register bit corresponding
to the cause of interrupt is enabled, this bit is set to 1.
D[3:2]
Reserved
D1
EP0IntStat
Shows a cause of interrupt indirectly.
When the EP0IntStat register has a cause of interrupt and the EP0IntEnb register bit corresponding to
the cause of interrupt is enabled, this bit is set to 1.
D0
RcvEP0SETUP
Shows a cause of interrupt directly.
Set to 1 when the received data are set to the EP0Setup_0 to EP0Setup_7 after the set up stage has been
completed. At the same time, the ForceSTALL bit, the ForceNAK bit and the ToggleStat bit of the EP-
0ControlIN and EP0ControlOUT registers are automatically set to 0, 1 and 1, respectively.