Endpoint N Last Write Frame Pointer Registers; Table 28-21 Endpoint N Last Write Frame Pointer Registers Description - Motorola DragonBall MC9328MX1 Reference Manual

28.3.17 Endpoint n Last Write Frame Pointer Registers

The Endpoint n Last Write Frame Pointer Registers hold the location of the most recently written frame.
The number of Endpoint n Last Write Frame Pointer Registers in the MC9328MX1 depends on the number
of endpoints configured.
USB_EP0_LWFP
USB_EP1_LWFP
USB_EP2_LWFP
USB_EP3_LWFP
USB_EP4_LWFP
USB_EP5_LWFP
BIT 31 30 29
TYPE r r r
0 0 0
RESET
BIT 15 14 13
TYPE r r r
0 0 0
RESET
Table 28-21. Endpoint n Last Write Frame Pointer Registers Description
Name
Reserved Reserved—These bits are reserved and should read 0.
Bits 31–6
LWFP Last Write Frame Pointer—Indicates the start of the last frame written into the FIFO. The LWFP can
Bits 5–0 be read and written for debugging purposes. For the frame retransmit function, the LRFP indicates
the point to begin retransmission of the data frame. For the frame discard function, the LWFP divides
the valid data region of the FIFO (the area in-between the read and write pointers) into framed and
unframed data. Data between the LRFP and write pointer is an incomplete frame, while data
between the read pointer and the LWFP is received as whole frames. When the FRAME bit is not
set, this pointer has no meaning.
MOTOROLA
Endpoint 0 Last Write Frame Pointer Register
Endpoint 1 Last Write Frame Pointer Register
Endpoint 2 Last Write Frame Pointer Register
Endpoint 3 Last Write Frame Pointer Register
Endpoint 4 Last Write Frame Pointer Register
Endpoint 5 Last Write Frame Pointer Register
28 27 26 25
r r r r
0 0 0 0
12 11 10 9
r r r r
0 0 0 0
USB Device Port
24 23 22 21 20
r r r r r
0 0 0 0 0
0x0000
8 7 6 5 4
r r r rw rw
0 0 0 0 0
0x0000
Description
Programming Model
Addr
0x0021204C
0x0021207C
0x002120AC
0x002120DC
0x0021210C
0x0021213C
19 18 17 16
r r r r
0 0 0 0
3 2 1 0
LWFP
rw rw rw rw
0 0 0 0
28-31