PXD20RM Datasheet, PDF (844/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

Table 27. NVUSRO field descriptions (continued)
Field
Description
STCU_EN
Self MBIST Enable (Read/Write)
1: Disable after reset
0: Enable after reset
Default manufacturing value before flash memory initialization is ‘1’.
UO[20:04]
User Options 20:04 (Read/Write)
The UO20-4 generic registers are reset based on the information stored in NVUSRO.
PAD3V5V[0]
High voltage supply for V_{DD_HV_B} domain
0: High voltage supply is 5.0 V
1: High voltage supply is 3.3 V
Default manufacturing value before flash memory initialization is ‘1’ (3.3 V) which should
ensure correct minimum slope for boundary scan.
PAD3V5V[1]
High voltage supply for V_{DD_HV_A} domain
0: High voltage supply is 5.0 V
1: High voltage supply is 3.3 V
Default manufacturing value before flash memory initialization is ‘1’ (3.3 V) which should
ensure correct minimum slope for boundary scan.
UO[01]
User Options 01 (Read/Write)
The UO01 generic register is reset based on the information stored in NVUSRO.
WATCHDOG_EN
0: Disable after reset
1: Enable after reset
Default manufacturing value before flash memory initialization is ‘1’
21.4 Functional description
The Flash module may operate in various modes. The modes that are available include:
• User mode
• Low Power mode
• Power Down mode
• UTest mode
Each of these modes are discussed in the following chapters, and more details provided about each mode.
21.4.1 User mode
In user mode the flash module may be read and written (register writes and interlock writes), programmed
or erased. The following sub-sections define all actions that may be performed in user mode.
21.4.1.1 Read and write
The default state of the flash module is read. The main and shadow address space can be read only in the
read state. The MCR is always available for read, except when the module is in Low Power mode or Power
Down mode. The flash module enters the read state on reset. The module is in the read state under four
sets of conditions:
21-32
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor