Nations N32G45 Series, User Manual

Page: 66 / 838

66 / 838
Nations Technologies Inc.
Tel
：
+86-755-86309900
Email
：
info@nationstech.com
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
SRAM. The maximum address range of SRAM is 0x2000 0000~0x2001 FFFF.
SRAM data cannot be retained in Stop2, Standby and VBAT modes; data in other working modes (Run/Sleep/Stop0)
can be retained normally.
The main features are as follows:

The maximum capacity is 128KB in total.

Support byte/half-word/word reading and writing

I/D/S/DMA1/MDA2/ETH can be accessed.

I/D BUS can run programs at full speed from Remap to SRAM.
3.2.4 R-SRAM
（
Retention SRAM
）
R-SRAM is also mainly used for code operation, storing variables and data or stacks during program execution, with
a total capacity of 16KB. The bus address of R-SRAM and SRAM are connected continuously. In application, SRAM
and R-SRAM can be treated as a piece of SRAM. In the maximum case, the physical address of R-SRAM No.0
corresponds to the bus start address of 0x2002 0000, and the corresponding bus address range is 0x2002
0000~0x2002 3FFF. R-SRAM supports read and write access of bytes, half words and words, and supports access to
SBus, DMA1, DMA2, and ETH.
Because the bus address of R-SRAM is continuously connected to SRAM, and for different product models, the
capacity of SRAM available for effective use is different, so for different product models, the bus start address of R-
SRAM are different.
R-SRAM supports Retention, which can retain data in VBAT and Standby modes (can be configured to retain or not
retain); other working modes (RUN/SLEEP/STOP0/STOP2) data can be retained by default; PWR is required to
control and manage its Retention.
Table 3-6 SRAM Capacity Configuration Table
SRAM capacity R-SRAM capacity SRAM bus address range R-SRAM bus address range
64KB 16KB 0x2000 0000~0x2000 FFFF 0x2001 0000~0x2001 3FFF
128KB 16KB 0x2000 0000~0x2001 FFFF 0x2002 0000~0x2002 3FFF
The main features of R-SRAM are as follows:

The total capacity is 16KB

Byte/halfword/word read and write

S/DMA1/DMA2/ETH can be accessed

The bus start address is continuously connected to the main memory SRAM

The bus start address changes with the main memory SRAM capacity

Retention is possible, data still needs to be retained in stop2 and standby modes (can be configured not to retain)