XC2200 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
User’s Manual
3-73
V2.1, 2008-08
MemoryX2K, V1.3
3.11.2
Stand-By RAM Registers
This section describes the SBRAM register interface in detail.
3.11.2.1 SBRAM Read Address Register
This register defines the word location to be read.
Reset by Power-On Reset.
Table 3-11
Registers Overview
Register Short
Name
Register Long Name
Offset
Address
Page Number
SBRAM_RADD
SBRAM Read Address
FEDC
H
SBRAM_WADD SBRAM Write Address
FEDE
H
SBRAM_DATA0 SBRAM Data Register 0
FEE0
H
SBRAM_DATA1 SBRAM Data Register 1
FEE2
H
SBRAM_RADD
SBRAM Read Address Register SFR (FEDC
H
/6E
H
)
Reset Value: 0000
H
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
MOD WA
0
RPTR
0
rwh rwh
r
rwh
r
Field
Bits
Type
Description
RPTR
[9:1]
rwh
Read Pointer
Selects the word address to be read from the
SBRAM. It is automatically incremented by 1 (i.e. to
the next word) when register DATA1 is read.
WA
14
rwh
Wrap Around
This bit indicates if a wrap-around of the read pointer
RPTR occurred due to the automatic address
increment.
0
An address wrap-around has not occurred.
1
An address wrap-around has been detected. It
has to be cleared by SW.