Texas Instruments TMS320DM357 用户手册
4.53 Frame Number Register (FRAME)
4.54 Index Register for Selecting the Endpoint Status and Control Registers (INDEX)
www.ti.com
Registers
The Frame Number Register (FRAME) is shown in
and described in
.
Figure 68. Frame Number Register (FRAME)
15
11
10
0
Reserved
FRAMENUMBER
R-0
R-0
LEGEND: R = Read only; -n = value after reset
Table 69. Frame Number Register (FRAME) Field Descriptions
Bit
Field
Value
Description
15-11
Reserved
0
Reserved
10-0
FRAMENUMBER
0-7FFh
Last received frame number
The Index Register for Selecting the Endpoint Status and Control Registers (INDEX) is shown in
and described in
Figure 69. Index Register for Selecting the Endpoint Status and Control Registers (INDEX)
7
4
3
0
Reserved
EPSEL
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 70. Index Register for Selecting the Endpoint Status and Control Registers (INDEX)
Field Descriptions
Bit
Field
Value
Description
7-4
Reserved
0
Reserved
3-0
EPSEL
0-Fh
Each transmit endpoint and each receive endpoint have their own set of control/status registers. EPSEL
determines which endpoint control/status registers are accessed.
determines which endpoint control/status registers are accessed.
Before accessing an endpoint's control/status registers, the endpoint number should be written to the
Index register to ensure that the correct control/status registers appear in the memory map.
Index register to ensure that the correct control/status registers appear in the memory map.
SPRUGH3 – November 2008
Universal Serial Bus (USB) Controller
117