6.1.2 MCU MEMORY MAP: XDATA SPACE
Table 3 - MCU XData Memory Map
8051 ADDRESS
DATA SPACE
External Memory or I/O Devices
ACCESS
External
0x3F30-0xFFFF
(IOR or IOW
active)
Internal Test Registers (reserved access)
External Memory or I/O Devices
0x3F00-0x3F2F
0x33F7-0X3EFF
DO NOT ACCESS
External
(IOR or IOW
active)
033F6
External ATA Interface I/O
External
(IOR or IOW
active)
0x31F8-0x33F5
0x31F0-0x31F7
0x30F4-0x31EF
External Memory or I/O Devices
External ATA Interface I/O
External
(IOR or IOW
active)
External
(IOR or IOW
active)
External Memory or I/O Devices
External
(IOR or IOW
active)
0X30F0-0X30F3
0X0700-0X30EF
Internal Test Registers (reserved access)
External Memory or I/O Devices
DO NOT ACCESS
External
(IOR or IOW
active)
0x0400-0x06FF
0x0000-0x03FF
768 Byte SRAM
(see Note 1)
Internal
External
(IOR or IOW
active)(see Note 1)
Note 1: This XDATA space is accessed using MOVX instructions. A region of 8051 Special Function Registers
(SFR) is also accessible at 0x0100 to 0x01FF addresses using the MOV instructions. In addition to the
normal 8051 SFRs, there are also numerous Runtime Registers in this SFR space. These Runtime
Registers are external to the 8051, but internal to the USB97C201.
SMSC DS – USB97C201
Page 15
Rev. 03/25/2002
PRELIMINARY
SMSC [ SMSC CORPORATION ]
