User manual
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This information applies to a product under development. Its characteristics and specifications are subject to change with-
out notice. Analog Devices assumes no obligation regarding future manufacturing unless otherwise agreed to in writing.
25REV. PrA
For current information contact Analog Devices at (781) 461-3881
ADSP-2192October 2000
USB REGIO (Read)
Address <15:15> = 1 indicates a read to the MCU register
space; Address <15:15> = 0 indicates a read to the DSP
register space. When accessing DSP register space, the
MCU must write the address to be read to the USB Regis-
ter I/O Address register.
Bit 15 of the USB Register I/O Address register starts the
transaction, and bit 14 is set to zero to indicate a READ.
The data read will be placed into the USB Register I/O Data
register.
USB REGIO (register read) is a three-stage control transfer
with an IN data stage. Stage 1 is the SETUP stage, stage 2
is the data stage involving the IN packet, and stage 3 is the
status stage. See Table 20 on page 25 for details about the
USB REGIO (register read) fields.
DSP Code Download
Since EP0 only has a max packet size of 8, downloading
DSP code on EP0 can be inefficient when operating on a
UHCI controller which only allows fixed amount of control
transactions per frame. Therefore, to gain better through-
put for code download, downloading of DSP code involves
synchronizing a control SETUP command on EP0 with
BULK OUT commands on endpoints 1, 2, or 3. Each end-
point has an associated DSP download address that is set by
using USB REGIO (Write) command.
5 wIndex (H) 1 0x00
6wLength (L) 10xXX
1
Length = XX bytes
7wLength (H) 10xYY
2
Length = YY bytes
1
XX is user-specified.
2
YY is user-specified.
Table 19. USB REGIO (Register Write)
Offset Field Size Value Description
0 bmRequest 1 0x40 Vendor Request, OUT
1 bRequest 1 0xA0 USB REGIO
2 wValue (L) 1 XXX Address <0:7>
3 wValue (H) 1 XXX Address <8:15>
4 wIndex (L) 1 0x00
5 wIndex (H) 1 0x00
6 wLength (L) 1 0x02 Length = 02 bytes
7 wLength (H) 1 0x00
Table 18. USB MCUCODE (Code Download) (Continued)
Offset Field Size Value Description
Table 20. USB REGIO (Register Read)
Offset Field Size Value Description
0 bmRequest 1 0xC0 Vendor Request, IN
1 bRequest 1 0xA0 USB REGIO
2 wValue (L) 1 XXX Address <0:7>