C8051T620/1/6/7 & C8051T320/1/2/3
92
Rev. 1.2
equal to twice the SYSCLK (USBCLK > 2 x SYSCLK). When this bit is set, the USB FIFO space is mapped
into XRAM space at addresses 0x0400 to 0x07FF. The normal on-chip XRAM at the same addresses can-
not be accessed when the USBFAE bit is set to 1.
Important Note
: The USB clock must be active when accessing FIFO space.
Figure 15.4. C8051T620/1 and C8051T320/1/2/3 USB FIFO Space and
XRAM Memory Map with USBFAE Set to 1
On-Chip XRAM
0x0000
Endpoint0
(64 bytes)
Free
(64 bytes)
0x0400
0x043F
0x0440
0x063F
0x0640
0x073F
0x0740
0x07BF
0x07C0
0x07FF
Endpoint1
(128 bytes)
Endpoint2
(256 bytes)
Endpoint3
(512 bytes)
USB FIFO Space
(USB Clock Domain)
0x03FF
On-Chip XRAM
0x0800
0xFFFF