Si1000/1/2/3/4/5
10.2. Special Function Registers
The special function register used for configuring XRAM access is EMI0CN.
SFR Definition 10.1. EMI0CN: External Memory Interface Control
Bit
Name
Type
Reset
R
0
R
0
R
0
R
0
0
0
7
6
5
4
3
2
1
0
PGSEL[3:0]
R/W
0
0
SFR Page = 0x0; SFR Address = 0xAA
Bit
7:4
3:0
Name
Unused
PGSEL
Read = 0000b; Write = Don’t Care.
XRAM Page Select.
The EMI0CN register provides 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. Since the upper (unused) bits of the register are always zero, EMI0CN deter-
mines which page of XRAM is accessed.
For Example:
If EMI0CN = 0x01, addresses 0x0100 through 0x01FF will be accessed.
If EMI0CN = 0x0F, addresses 0x0F00 through 0x0FFF will be accessed.
Function
122
Rev. 1.0
SILABS [ SILICON LABORATORIES ]
