Static RAM (SRAM)
Freescale Semiconductor
11-2
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
11.2.1
SRAM Base Address Register (RAMBAR)
The configuration information in the SRAM base-address register (RAMBAR) controls the operation of
the SRAM module.
•
The RAMBAR holds the SRAM base address. The MOVEC instruction provides write-only access
to this register.
•
The RAMBAR can be read or written from the debug module.
•
All undefined bits in the register are reserved. These bits are ignored during writes to the
RAMBAR and return zeroes when read from the debug module.
•
A reset clears the RAMBAR’s valid bit. This invalidates the processor port to the SRAM (The
RAMBAR must be initialized before the core can access the SRAM.) All other bits are unaffected.
NOTE
Do not confuse this RAMBAR with the SCM RAMBAR in
“Memory Base Address Register (RAMBAR).”
Although similar, this core
RAMBAR enables core access to the SRAM memory, while the SCM
RAMBAR enables peripheral (e.g., DMA and FEC) access to the SRAM.
The RAMBAR contains several control fields. These fields are shown in
.
Table 11-1. SRAM Programming Model
Rc[11:0]
1
1
The values listed in this column represent the Rc field used when accessing the core registers via the BDM port. For more
information see
Register
Width
(bits)
Access
Reset Value
Written
w/ MOVEC
Section/Page
Supervisor Access Only Registers
0xC05
RAM Base Address Register (RAMBAR)
32
R/W
See Section
Yes
Rc[11:0]: 0x0C05 (RAMBAR)
Access: User write-only
Debug read/write
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12
11
10
9
8
7
6
5
4
3
2
1
0
R
BA
0
0
0
PRIU PRIL SPV WP
0
0
C/I SC SD UC UD V
W
Reset U U U U U U U U U U U U U U U U U 0
0
0
0
0
0
U
0
0
U
U
U
U
U
0
Figure 11-1. SRAM Base Address Register (RAMBAR)
Table 11-2. RAMBAR Field Descriptions
Field
Description
31–15
BA
Base Address. Defines the 0-modulo-32K base address of the SRAM module. By programming this field,
the SRAM may be located on any 32-Kbyte boundary (16-Kbyte boundary for the MCF52230 and
MCF52231).
14–12
Reserved, must be cleared.
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60
