GD32W51x User Manual
122
which consist of MSBs (RADDR[31:RS] field of ICACHE_CFGx) and LSBs
(AHB_ADDR_in[RS-1:0]).
Figure 4-2. ICACHE remapping address
A
HB
_A
DD
R
_in
[
RS
-1
:0
]
0
0
31
31
RS
RS
RS-1
RS-1
AHB_ADDR_in
AHB_ADDR_out
0
1
RADDR[31:RS]
000:BADDR[28:RS]
==
Region x
address
When programming BADDR and RADDR field in ICACHE_CFGx, it is notable that if
programmed value is larger than expected (MSBs), the unnecessary extra LSBs are
bypassed.
Table 4-2. ICAHCE remap region size
Region size
(
MB
)
Base address
(
MSBs
)
Rem ap address
(
MSBs
)
2
8
11
4
7
10
8
6
9
16
5
8
32
4
7
64
3
6
128
2
5
The remapping operation is configured by programming ICACHE_CFGx register, the
programming operation is merely done in case that ICACHE is disabled. While, once the
EN bit in ICACHE_CFGx register is set, even though ICAHCE is disabled, or the
transaction is uncacheable, the corresponding region x is enabled and then remap
operation is generated. The SIZE bit in ICACHE_CFGx register is used to configure
remap region size. The size of region is a power of two multiple in 2 Mbytes, the minimum
region size is 2 Mbytes and the maximum region size is 128 Mbytes.
Through configuring the OBT bit in ICACHE_CFGx, the type of AHB burst is configured
as INCR4.
INCR4 is used for external memories accessed through QSPI interface. INCR4 burst size
equals to cache line size. INCR4 burst start address equals to cache line boundary
aligned address.