CDR3 Flash (UC3F) EEPROM
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
21-29
With STOP = 1, the UC3F module enters a low power state by shutting down internal timers and bias
generators. A stop recovery time of 1
µ
s is required when clearing the STOP bit to exit stop operation. The
BIU should allow 1
µ
s following the negation of the STOP bit so that internal bias generators used by the
array may recover to normal levels prior to initiating any UC3F array accesses.
NOTE
The UC3F cannot be stopped while the array is being programmed or erased
since the STOP bit is write locked by SES = 1.
21.3.10 Disabled
The UC3F module can be disabled by clearing the FLEN bit in the IMMR register (see
“System Configuration and Protection Registers
”). While disabled, the UC3F module is completely shut
down. The register block and array are not accessible in this mode, and all circuits which draw any DC
power are disabled to eliminate power consumption. In addition,the module can be disabled by setting the
STOP bit in the UC3FMCR register (see
Section 21.2.1.2, “UC3F EEPROM Configuration Register
”).
If the UC3F module is disabled while programming or erasing, the HSUS bit in the UC3FCTL register is
asserted (HSUS = 1) to suspend the current program or erase operation. When the UC3F module is
re-enabled, the suspended program or erase operation may be resumed by writing the HSUS bit to a 0.
NOTE
While there should be no harmful side effects resulting from disabling the
UC3F module while in program or erase operation, it is not recommended
that program or erase operation be suspended in this manner.
When disabled, the power used by the UC3F is reduced to leakage levels; otherwise, the UC3F module is
enabled for accesses. For example, recovering from a stop operation (STOP = 1), there is a recovery time
of 1
µ
s for internal biases to reach to operating levels.
21.3.11 Censored Accesses and Non-Censored Accesses
The UC3F EEPROM has a censorship mechanism which provides for several censorship states. The
censorship mechanism is used to increase restrictions in accessing Flash data. Four bits in UC3FMCR are
used to configure the UC3F censorship state. These bits are:
•
ACCESS—Enables a UC3F EEPROM to bypass the censorship.
•
FIC—Overrides CENSOR[0:1] to force information censorship.
•
CENSOR[0:1]—Determine the censorship state of the UC3F.
The device has two relevant modes used by the UC3F EEPROM to select the type of censorship. The first
mode, which is uncensored mode, provides no censorship. In uncensored mode the ACCESS and
CENSOR[0:1] bits are irrelevant. The second mode, censored mode, enables the UC3F EEPROM to
exercise censorship based on the state of ACCESS, FIC, and CENSOR[0:1]. The device will enter
censored mode only if one of following events occurs:
•
booting from external memory
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...