NO:
W90P710 Programming Guide
VERSION:
2.1
PAGE:
31
The above information is the exclusive intellectual property of Winbond Electronics and shall not be disclosed,
distributed or reproduced without permission from Winbond.
Table No.: 1200-0003-07-A
Reset Go
Does the system have
been initialized?
Calculating the correct instruction fetch address
after remapping boot FLASH/ROM base address
Set the EBICON, ROMCON, SDCONF0,
SDCONF1, SDTIME0, and SDTIME1 at the same
time by store multiple instruction.
Branch to the correct instruction fetch address
calculated before.
Example:
EBICON = 0x000509C1
ROMCON = 0xFFA00724 (base=0x7FD00000 size=256KB)
SDCONF0 = 0x000010ED (base=0x00000000 size=32MB )
SDCONF0 = 0x040010ED (base=0x02000000 size=32MB )
SDTIME0 = 0x000007FF
SDTIME0 = 0x000007FF
Execute boot software
Calculating the correct instruction fetch address
after remapping boot FLASH/ROM base address
Boot FLASH/ROM 256KB
0x00000000
0x00040000
0x7FFFFFFF
SDRAM BANK 1
0x00000000
0x02000000
SDRAM BANK 0
Boot FLASH/ROM 256KB
0x04000000
0x7FFFFFFF
Before Initialization
After Initialization
0x7FD000000
Figure 2-4 is the boot flow of Boot Monitor with remapping. The flow chart shows that most of the
EBI control registers, EBICON, ROMCON, SDCONF, SDTIME should beware initialized as soon as
possible immediately after reset. Each value of these control register must be known before these
registers were configured. Because on doing of remapping, the control registers should be set by store
multiple instructions (
STMIA
). The store multiple instructions guarantee to complete the memory
initialization before next instruction execution. The system memory maps before initialization and after
initialization are shown as above, too. After system reset, the system can access the 256KB boot
FLASH/ROM. After the system initialization the memory map becomes the
After Initialization of
Figure
2-4.
