XC68HC705F32 Motorola, XC68HC705F32 Datasheet - Page 178

• Manufacturer Part Number: XC68HC705F32
• Description: MICROCONTROLLER
• Manufacturer: Motorola

A
A.3.2
The MC68HC705F32 has 32256 bytes of EPROM located from $8000 to $FDFF, plus 16 bytes of
user vectors from $FFF0 to $FFFF. Up to 16 bytes of EPROM can be programmed simultaneously
by correctly manipulating the bits in the EPROM programming register.
A.3.2.1
EPGM — EPROM program control
ELATCH and EPGM cannot be set on the same write operation. EPGM can only be set if ELATCH
is set. EPGM is automatically cleared when ELATCH is cleared.
ELATCH — EPROM latch control
ELATCH causes address and data buses to be latched when a write to EPROM is carried out. The
EPROM cannot be read if ELATCH = 1. This bit should not be set unless a programming voltage
is applied to the VPP pin.
A.3.2.2
The following steps should be taken to program a byte of EPROM:
If the address bytes A15–A4 do not change, i.e. all bytes are located within the same 16 byte
address block, then multibyte programming is permitted. The multibyte programming facility allows
up to 16 bytes of data to be written to the desired addresses after the ELATCH bit has been set.
MOTOROLA
A-8
EPROM programming (PROG)
1 (set)
0 (clear) –
1 (set)
0 (clear) –
1) Apply the programming voltage V
2) Set the ELATCH bit.
3) Write to the EPROM address.
4) Set the EPGM bit for a time t
5) Clear the ELATCH bit.
EPROM programming register (PROG)
EPROM programming operation
EPROM
–
–
Programming power connected to the EPROM array.
Programming power disconnected from the EPROM array.
EPROM address and data buses configured for programming.
EPROM address and data buses configured for normal reads
$001D
Address
bit 7
0
EPGM
MC68HC705F32
0
bit 6
PP
to apply the programming voltage.
to the IRQ pin.
0
bit 5
0
bit 4
0
bit 3
ELATCH
bit 2
bit 1
0
MC68HC05F32
EPGM 0000 0000
bit 0
on reset
State
TPG