Hub Specification Sheet

Converting from Intel 8x930Ax to Cypress EZ-USB
5
10.Passive Networks
Both the 8x930Ax and EZ-USB have active-HIGH RESET
pins, but while the 8x930Ax requires only a capacitor to
V
CC
, the EZ-USB family parts require a resistor-capacitor
network.
11. Connect any programmable I/Os that were used to gen-
erate I
2
C signals directly to the EZ-USB I
2
C port.
If a peripheral required an I
2
C bus master, the 8x930Ax
would require the use of a programmable I/O along with
the appropriate firmware to emulate the I
2
C bus. EZ-USB
has a dedicated I
2
C port that is a master and can be used
to control other I
2
C devices on the peripheral board.
Additional Firmware Issues To Consider When
Converting
1. Compile as 8051 (not 251)
Since the EZ-USB core operates in the 8051 mode only,
you must recompile your application in only this configura-
tion. The ‘251 mode uses different instructions and formats
and will not work. Most compilers for the 8051 family have
compile switches that make this translation transparent.
2. Add EZ-USB frameworks code
• Handles endpoint 0 transfers (getdesc…)
• Provides hooks to USB events
• Performs ReNumeration
All of the firmware that is required to handle default device
requests, set up the processor environment, perform Re-
Numeration, and set up hooks to all of the USB events is
included in the Application Frameworks which is included
in the EZ-USB Developer’s Kit. Although much of the end-
point 0 traffic is handled by the EZ-USB Smart core, the
8051 still has USB overhead to handle. The frameworks
code serves as a good example of how to handle the re-
maining processing necessary by the 8051.
3. Remove control transfer code
Since the EZ-USB Smart core automatically handles
much of the Endpoint 0 Control transfer processing, a
good portion of the firmware required by the 930 can be
removed from the code after conversion.
4. Use Turbo transfer mode when USB performance is
desired
To utilize the full bandwidth of the USB and still achieve the
maximum processing power, all data transfers for
high-bandwidth data should use the Turbo transfer mode.
The firmware required to perform these transfers is very
simple and is written in assembly to utilize the full speed
of this mode. These transfers will replace standard XDATA
accesses in the 930 firmware.
5. Remove 251 configuration setup
Since there are no configuration features that require set-
up for the 8051, the configuration setup code for the ‘251
can be removed.
6. Endpoint data is in RAM, not FIFOs
The 930 provides all of the bulk endpoint data in FIFOs,
making the processor read each byte out in series to pro-
cess a block of endpoint data. The EZ-USB architecture
places its data in RAM, which can be accessed in any
order necessary. This process can greatly reduce the pro-
cessing overhead, especially when processing control
transfers.
7. EZ-USB registers are in XDATA space, not SFRs
All of the registers in the EZ-USB chip are contained in the
XDATA memory space. This requires MOVX instructions to
access them.
8. I/O Ports are in XDATA space
The Intel 8x930Ax family uses SFR (Special Function
Register) bits to control their I/O port pins. The EZ-USB
family memory maps I/O port control registers, accessible
with MOVX instructions. Thus bit set and clear instructions
cannot be used with the EZ-USB I/O Ports.
Case Example– Zoran Video Inlet Reference
Design
Zoran manufacturers a Motion JPEG device, ZR36060, per-
forming on-the-fly hardware compression and yielding 30 fps
performance for video captures at CIF resolutions over USB.
With the advent of supporting JPEG compression, end users
can still capture video frame and maintain sharp images dur-
ing the capture. The Video Inlet reference design offers the
ability for the consumer to use a standard consumer video-
Table 2. Product Options
Part Number Package
RAM
Size
I/O Rate
(Bytes/s)
# of Prog
I/Os
8-bit
Databus?
ISO
Support?
AN2121SC 44 PQFP 4K 600K 16 No Yes
AN2122SC 44 PQFP 4K 600K 16 No No
AN2122TC 48 TQFP 4K 600K 19 No No
AN2125SC 44 PQFP 4K 2M 8 Yes Yes
AN2126SC 44 PQFP 4K 2M 8 Yes No
AN2126TC 48 TQFP 4K 2M 11 Yes No
AN2131SC 44 PQFP 8K 600K 16 No Yes
AN2135SC 44 PQFP 8K 2M 8 Yes Yes
AN2136SC 44 PQFP 8K 2M 8 Yes No
AN2131QC 80 PQFP 8K 2M 24 Yes+Addr Yes