Register Descriptions; Flash Memory Control Register 1 (Flmcr1) - Hitachi H8/3062 Hardware Manual

18.3

Register Descriptions

18.3.1

Flash Memory Control Register 1 (FLMCR1)

Bit 7
FWE
— *
Initial value
Read/Write R
Note: * Determined by the state of the FWE pin.
FLMCR1 is an 8-bit register used for flash memory operating mode control.
Program-verify mode or erase-verify mode for addresses H'00000 to H'3FFFF is entered by setting
the SWE bit when FWE = 1, then setting the PV or EV bit. Program mode for addresses H'00000
to H'3FFFF is entered by setting the SWE bit when FWE = 1, then setting the PSU bit, and finally
setting the P bit. Erase mode for addresses H'00000 to H'3FFFF is entered by setting the SWE bit
when FWE = 1, then setting the ESU bit, and finally setting the E bit. FLMCR1 is initialized by a
reset, and in hardware standby mode and software standby mode. Its initial value is H'80 when a
high level is input to the FWE pin, and H'00 when a low level is input. In mode 6 the FWE pin
must be fixed low since flash memory on-board programming modes are not supported. When the
on-chip flash memory is disabled, a read access to this register will return H'00, and writes are
invalid.
When setting bits 6 to 0 in this register, one bit must be set one at a time. Writes to the SWE bit in
FLMCR1 are enabled only when FWE = 1; writes to bits ESU, PSU, EV, and PV only when FWE
= 1 and SWE = 1; writes to the E bit only when FWE = 1, SWE = 1, and ESU = 1; and writes to
the P bit only when FWE = 1, SWE = 1, and PSU = 1.
Notes: 1. The programming and erase flowcharts must be followed when setting the bits in this
register to prevent erroneous programming or erasing.
2. Transitions are made to program mode, erase mode, program-verify mode, and erase-
verify mode according to the settings in this register. When reading flash memory as
normal on-chip ROM, bits 6 to 0 in this register must be cleared.
Bit 7—Flash Write Enable (FWE): Sets hardware protection against flash memory
programming/erasing.
Bit 7
FWE Description
0 When a low level is input to the FWE pin (hardware-protected state)
1 When a high level is input to the FWE pin
528
6 5
SWE ESU
0 0
R/W R/W
4 3
PSU EV
0 0
R/W R/W
2 1
PV E
0 0
R/W R/W
0
P
0
R/W