2-IN/OUT (paired), 4-IN and 4-OUT can use 0x1B40-0x1CBF as data memory. Chapter
3 gives full details of the EZ-USB memory map.
Note
AN2122 endpoint memory starts at 0x1C00 and AN2126 endpoint memory starts at
address 0x7C00.
Note
Uploads or Downloads to unused bulk memory can be done only at the Mirrored (low)
addresses shown in Table 6-3.
6.10 Data Toggle Control
The EZ-USB core automatically maintains the data toggle bits during bulk, control and
interrupt transfers. As explained in Chapter 1, "Introducing EZ-USB," the toggle bits are
used to detect certain transmission errors so that erroneous data can be re-sent.
In certain circumstances, the host resets its data toggle to “DATA0”:
•
•
•
After sending a Clear_Feature: Endpoint Stall request to an endpoint.
After setting a new interface.
After selecting a new alternate setting.
In these cases, the 8051 can directly clear the data toggle for each of the bulk/interrupt/
control endpoints, using the TOGCTL register (Figure 6-5).
TOGCTL
Data Toggle Control
7FD7
b7
b6
b5
b4
b3
b2
b1
b0
Q
S
R
IO
0
EP2
EP1
EP0
R
x
R/W
x
R/W
x
R/W
x
R/W
x
R/W
x
R/W
x
R/W
x
Figure 6-5. Bulk Endpoint Toggle Control
EZ-USB TRM v1.9
Chapter 6. EZ-USB CPU
Page 6-11
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