
CDR3 Flash (UC3F) EEPROM
MPC561/MPC563 Reference Manual, Rev. 1.2
21-4
Freescale Semiconductor
21.1
UC3F Interface
The UC3F module contains a memory interface (MI) and an array core. The MI controls access of the array
core and register block in the UC3F module.
The interface signals to the UC3F module consist of address inputs, data inputs, data outputs, a simple set
of control signals for read and write operations, a set of register selects, and a set of register outputs which
are used by the BIU. Three required supply pins power the module: VDDF, VSSF, and VFLASH.
The UC3F module is a fully asynchronous module and does not require a clock input for operation. All
required clocks are generated internally using an internal oscillator, external test clock input, or internal
delay circuits.
21.1.1
External Interface
The UC3F EEPROM module uses external pins to provide power supplies. These pins are listed in
.
Table 21-1. UC3F External Interface Signals
Mnemoni
c
I/O Type
Description
Comments
VDDF
Power Pin
UC3F power supply
To reduce noise in the read path no other circuits should be
connected to the UC3F VDDF supply pin.This VDD pin must be
isolated from all other VDD pins inside the device. The specified
voltage range during operation is 2.6 V
± 0.1 V.
VSSF
Ground Pin
UC3F ground
To reduce noise in the read path no other circuits should be
connected to the UC3F VSSF supply. This VSS pin must be isolated
from all other VSS pins inside the device.
VFLASH
Power Pin
UC3F 5-V power supply VFLASH provides a 5-V supply to the UC3F module which is used
for read, program, and erase operations. VFLASH must be in the
range of 4.75 V to 5.25 V (5 V
± 5%) during operation.
EPEE
External
Program/Eras
e
EPEE pin status
The EPEE bit monitors the state of the external program/erase
enable (EPEE) input. The UC3F module samples the EPEE input
when EHV is asserted and holds that sampled state until EHV is
negated.
B0EPEE
Block 0
External
Program/Eras
e
Block 0
EPEE pin status
The B0EM bit monitors the state of Block 0 EPEE, B0EPEE, input.
The UC3F module samples the B0EPEE input when EHV is
asserted and holds that sampled value until EHV is negated.
If B0EM = 1 when EHV is asserted, high voltage operations such
as program or erase are enabled for either small block 0 or the
lowest numbered block of the UC3F array regardless of the state
of EPEE.
If B0EM = 0 when EHV is asserted, high voltage operations are
disabled for small block 0 or the lowest numbered block of the
UC3F array regardless of the state of EPEE.