C8051F321-GMR Datasheet, PDF (115/250 Pages) Silicon Laboratories – Full Speed USB, 16 k ISP FLASH MCU Family

C8051F320/1
0x03FF
User XRAM Space
(System Clock Domain)
User XRAM
(1024 bytes)
0x0000
0x07FF
0x07C0
0x07BF
0x0740
0x073F
0x0640
0x063F
0x0440
0x043F
0x0400
Endpoint0
(64 bytes)
Endpoint1
(128 bytes)
Endpoint2
(256 bytes)
Endpoint3
(512 bytes)
Free
(64 bytes)
USB FIFO Space
(USB Clock Domain)
Figure 12.2. XRAM Memory Map Expanded View
SFR Definition 12.1. EMI0CN: External Memory Interface Control
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Reset Value
-
-
-
-
-
PGSEL2 PGSEL1 PGSEL0 00000000
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0 SFR Address:
0xAA
Bits7–3:
Bits2–0:
Unused: Read = 00000b. Write = don’t care.
PGSEL[2:0]: XRAM Page Select Bits.
The XRAM Page Select Bits provide the high byte of the 16-bit external data memory
address when using an 8-bit MOVX command, effectively selecting a 256-byte page of
RAM. The upper 5-bits are "don't cares", so the 2k address blocks are repeated modulo over
the entire 64k external data memory address space.
Rev. 1.4
115