D12320VF25IV Datasheet, PDF (825/1304 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 19 ROM
19.13.3 Flash Memory Operating Modes
Mode Transitions: When the mode pins and the FWE pin are set in the reset state and a reset-
start is executed, the chip enters one of the operating modes shown in figure 19.30. In user mode,
flash memory can be read but not programmed or erased.
Flash memory can be programmed and erased in boot mode, user program mode, and PROM
mode.
MD1 = 1,
MD2 = 1,
FWE = 0
User mode
(on-chip ROM
enabled)
RES = 0
RES = 0
FWE = 1,
SWE = 1
FWE = 0
or SWE = 0
User
program mode
Reset state
FWE = 1,
MD1 = 1,
MD2 = 0
*
RES = 0
RES = 0
PROM mode
On-board programming mode
Boot mode
Notes: Only make a transition between user mode and user program mode when the CPU is
not accessing the flash memory.
* MD0 = 0, MD1 = 0, MD2 = 0, P66 = 1, P65 = 0, P64 = 0
Figure 19.30 Flash Memory Mode Transitions
Rev.6.00 Sep. 27, 2007 Page 793 of 1268
REJ09B0220-0600