XC68HC705F32 Motorola, XC68HC705F32 Datasheet - Page 41

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

ER1, ER0 — Erase select bits
ER1 and ER0 are used to select either single byte programming or one of three erase modes:
byte, block, or bulk.
readable and writable and are cleared by reset.
LATCH — EEPROM latch bit
When set, the LATCH bit configures the EEPROM address and data buses for programming. In
addition, writes to the EEPROM array cause the address and data buses to be latched. This bit is
readable and writable, but reads from the EEPROM array are inhibited if the LATCH bit is set and
a write to the EEPROM space has taken place. When this bit is clear, address and data buses are
configured for normal operation. Reset clears this bit.
EERC — EEPROM RC oscillator control
When this bit is set, the EEPROM memory array uses the internal RC oscillator instead of the CPU
clock. After setting the EERC bit, the user should wait a time t
stabilize. This bit is readable and writable and should be set by the user when the internal bus
frequency falls below 1.5MHz. Reset clears this bit.
MC68HC05F32
– In byte erase mode, only the selected byte is erased.
– In block erase mode, a 32-byte block of EEPROM is erased. The EEPROM
– In bulk erase mode, the entire 256 bytes of EEPROM are erased.
1 (set)
0 (clear) –
1 (set)
0 (clear) –
memory space is divided into four 64-byte blocks ($0400 – $043F, $0440 –
$047F, $0480 – $04BF and $04C0 – $04FF) and performing a block erase
on any address within a block will erase the entire block.
–
–
Table 3-2
EEPROM address and data buses are configured for programming.
EEPROM address and data buses are configured for normal
operation.
Use internal RC oscillator for EEPROM.
Use CPU clock for EEPROM.
shows the mode selected for each bit configuration. These bits are
MEMORY AND REGISTERS
Table 3-2 Erase modes
ER1
0
0
1
1
ER0
0
1
0
1
Block erase
Byte erase
Bulk erase
Program
Mode
RCON
to allow the RC oscillator to
MOTOROLA
3-7
3