Ameba-D Application Note
Application Note All information provided in this document is subject to legal disclaimers. © REALTEK 2020. All rights reserved.
21
A4 (SRAM): This section is read-write data in SRAM.
P1 (SRAM): This is BSS section in SRAM.
1.5.2
Memory Size
1.5.2.1
Memory Size in SRAM
There are two sections resident in SRAM, which are A4 and P1. As we can see from the map file, for standard SDK, these two sections use
almost all of the memory space from SRAM (476KB).
A4 has size 0x17ad7.
P1 has size 0x5dfc8.
So totally 0 0x5dfc8 = 470K bytes memory in SRAM is used.
The total SRAM space is defined in project\realtek_amebaD_va0_example\EWARM-RELEASE\rtl8721d_memory_layout_is.icf.
define symbol __ICFEDIT_region_HS_BD_RAM_NS_start__
= 0x10005000;
define symbol __ICFEDIT_region_HS_BD_RAM_NS_end__
= 0x1007C000-1;
For this case, the total size of SRAM is 0x1007C000 ─ 0x10005000 = 0x77000 = 476K bytes, there is still 6K (= 476K ─ 470K) bytes free SRAM
space.
1.5.2.2
Memory Size in PSRAM
There is one section in PSRAM called A7, the memory space from PSRAM (4MB).
A7 has size 0x54800.
So totally 0x54800 = 338K bytes memory in PSRAM is used.
1.5.2.3
Memory Size in XIP
XIP can only place text section, so there is only one section called A5.
A5 has size 0x8afe8.
