4
N S 9 7 5 0 B - A 1 E r r a t a , R e v . F 0 9 / 2 0 0 6
U S B O V R a n d U S B P W R
The maximum bytes in each DMA buffer descriptor is limited to 16 bytes.
The maximum skid rate can be up to 16 characters.
The serial monitor thread is changed to handle the missing CTS interrupt.
See the appropriate (6.0 or 6.3) NET+OS SW toolkit (on the Web) for the required software
workarounds.
Hardware workaround: For each UART, externally clock the CTS signal with the Txd_n signal to
guarantee that CTS will not be seen de-asserting at the start of a character.
USB OVR and USB PWR
The USB OVR (over current) input on gpio[16] is not shown in the GPIO MUX pinout tables. The
polarity of this signal cannot be changed. It is true high, normally requiring an external inverter
and noise filter to prevent false indications of over current.
This table shows the corrections to GPIO[16] in the pinout table:
Updates are required to the BSP to change gpio[16] from mode 00 to mode 02. Timer 11 is
disabled, allowing USB OVR to be recognized by the USP IP. Even though Timer 11 is disabled, the
Timer clock select field must be set to 111-External pulse event to set GPIO[16] to an input.
If you are using USB Host, GPIO[16] must be reserved for the USB OVR function.
CTS[n]
74LV74
D
Q
CLK
Q
PR
CL
TXD[n]
UART CTS Flow
Control workaround
R2
0 OHM
CTS[n]
U2
RESET
TXD[n]
Add R2 instead of U2 to bypass this circuit
CTS_mod[n]
Signal
Mode
Description
00
01
02
03 (default)
Reserved output
1284 nFault (peripheral driver, duplicate)
Timer 11 (duplicate), USB OVR
GPIO 16
gpio[16]
Содержание Errata NS9750B-A1
Страница 7: ......
