R8A66597BG RENESAS [Renesas Technology Corp], R8A66597BG Datasheet - Page 135

• Manufacturer Part Number: R8A66597BG
• Description: ASSP (USB2.0 2 Port Host/1 Port Peripheral Controller)
• Manufacturer: RENESAS [Renesas Technology Corp]

R8A66597FP/DFP/BG
3.4.1.3 Buffer Area
3.4.1.4 Buffer Memory Specifications (Single/Double Setting)
R e v 1 . 0 1
Table 3.14shows the buffer memory map for the controller. The buffer memory consists of a fixed area in which pipes
are pre-assigned and a user area in which the user can set blocks as needed. The DCP buffer is a fixed area used
only for control read transfers and control write transfers. Pipes 6-9 are pre-assigned to areas. When not using one of
these pipes, the user can assign one of pipes 1-5 to the unused pipe area and utilize as a user area. Be careful to set
the pipe areas so that they do not overlap. In addition, set the buffer size so that it is larger or equal than the maximum
packet size.
Pipes 1-5 can be specified as single or double buffers with the PIPExCFG register DBLB bit. The double buffer is a
function that assigns doulbe areas in the specified memory with the PIPEBUF register BUFSIZE bit for one pipe.
Figure 3.14 is a double buffer setting example of PIPE1 and PIPE3 as seen in the buffer memory map example.
O c t 1 7 , 2 0 0 8
0 – 3
4
5
6
7
8 – 135 (0x87)
Buffer Memory
p a g e 1 3 5 o f 1 8 3
Number
Table 3.14 Buffer Memory Map
256 bytes
(64 bytes x 4 blocks)
64 bytes
64 bytes
64 bytes
64 bytes
8192 bytes
(64 bytes x 128 blocks)
Buffer Size
DCP-only fixed
area
PIPE 6 fixed area
PIPE 7 fixed area
PIPE 8 fixed area
PIPE 9 fixed area
PIPE 1-5
Assignable PIPE