Samsung S5PC110 Manual page 941

S5PC110_UM
5.8.7 DEVICE MODE REGISTERS (DEVICE GLOBAL REGISTERS)
These registers are visible only in Device mode and must not be accessed in Host mode, as the results are
unknown. Some of them affect all the endpoints uniformly, while others affect only a specific endpoint. Device
Mode registers fall into two categories:
•
Device Global registers
•
Device logical endpoint-specific registers
5.8.7.1 Device Configuration Register (DCFG, R/W, Address = 0xEC00_0800)
This register configures the core after power-on or after certain control commands or enumeration. Do not make
changes to this register after initial programming.
DCFG Bit
ResValid [31:26] Resume Validation Period
PerSchInt [25:24] Periodic Scheduling Interval
vl
DescDMA [23]
Reserved [22:13] -
This field controls the period when the core resumes from a
suspend. When this bit is set, the core counts for the ResValid
number of clock cycles to detect a valid resume. This field is
effective only when DCFG.Ena32KHzSusp is set
PerSchIntvl must be programmed only for Scatter/Gather DMA
mode. This field specifies the amount of time the Internal DMA
engine must allocate for fetching periodic IN endpoint data. Based
on the number of periodic endpoints, this value must be specified as
25, 50 or 75% of (micro) frame.
When any periodic endpoints are active, the internal DMA engine
•
allocates the specified amount of time in fetching periodic IN
endpoint data
When no periodic endpoints are active, then the internal DMA
•
engine services non-periodic endpoints, ignoring this field.
After the specified time within a (micro)frame, the DMA switches to
•
fetching for non-periodic endpoints.
2'b00: 25% of (micro)frame.
•
2'b01: 50% of (micro)frame.
•
2'b10: 75% of (micro)frame.
•
2'b11: Reserved.
•
Enable Scatter/gather DMA in device mode.
This bit must be modified only once after a reset. The following
combinations are available for programming:
GAHBCFG.DMAEn=0,DCFG.DescDMA=0 => Slave mode
•
GAHBCFG.DMAEn=0,DCFG.DescDMA=1 => Invalid
•
GAHBCFG.DMAEn=1,DCFG.DescDMA=0 => Buffered DMA mode
•
GAHBCFG.DMAEn=1,DCFG.DescDMA=1 => Scatter/Gather DMA
•
mode
Description
5 USB2.0 HS OTG
R/W Initial State
R/W 6'h2
R/W 2'b00
R/W 1'b0
- 10'h100
5-65