AT90SCR100 datasheet(207/433 Pages) ATMEL

tên linh kiện	AT90SCR100

Giải thích chi tiết về linh kiện	8-bit Microcontroller for Smart Card Readers

PDF	433 Pages

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nhà sản xuất	ATMEL [ATMEL Corporation]

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207

TPR0327AY–SMS–30Jan09

AT90SCR100

Figure 17-2.

USB-IC Design Recommendations

17.4

Memory Management

The controller does only support the following memory allocation management:

The reservation of a Pipe can only be made in the growing order (Pipe 0 to the last Pipe). The

firmware shall thus configure them in the same order.

The reservation of a Pipe “ki” is done when its ALLOC bit is set. Then, the hardware allocates

the memory and insert it between the Pipe “ki-1” and “ki+1”. The “ki+1” Pipe memory “slides” up

and its data is lost. Note that the “ki+2” and upper Pipe memory does not slide.

Clearing a Pipe enable (PEN) does not clear neither its ALLOC bit, nor its configuration (PSIZE,

PBK). To free its memory, the firmware should clear ALLOC. Then, the “ki+1” Pipe memory auto-

matically “slides” down. Note that the “ki+2” and upper Pipe memory does not slide.

The following figure illustrates the allocation and reorganization of the USB memory in a typical

example:

AT90SCR100

CC4

CC8

D+

D-

30K

Ω < RPDH < 150KΩ

RPDH

Bidirectional

Commutator

GPIO

Can be any

control pin

AT90SCR100 bảng dữ liệu(PDF) 207 Page - ATMEL Corporation