pic32mx320f064h Microchip Technology Inc., pic32mx320f064h Datasheet - Page 121

no-image

pic32mx320f064h

Manufacturer Part Number
pic32mx320f064h
Description
64/100-pin General Purpose, 32-bit Flash Microcontrollers
Manufacturer
Microchip Technology Inc.
Datasheet

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
pic32mx320f064h-40I/PT
Manufacturer:
Microchip Technology
Quantity:
10 000
Part Number:
pic32mx320f064h-40I/PT
Manufacturer:
MICROCHIP/微芯
Quantity:
20 000
Part Number:
pic32mx320f064h-40V/PT
Manufacturer:
Microchip Technology
Quantity:
10 000
Part Number:
pic32mx320f064h-80I/PT
Manufacturer:
Microchip Technology
Quantity:
10 000
Part Number:
pic32mx320f064h-80V/PT
Manufacturer:
Microchip Technology
Quantity:
10 000
Part Number:
pic32mx320f064hT-40I/PT
Manufacturer:
Microchip Technology
Quantity:
10 000
6.5
For optimal performance, PFMWS(CHECON<2:0>)
must be programmed to the minimum value possible.
There are two parameters that determine this value:
Flash Access Time - 50 nSec for the PIC32MX pro-
cessor family.
CPU Core frequency - The Core frequency is pro-
grammable. Care must be taken when changing fre-
quencies to make sure that there are enough wait
states to prevent any Flash memory access timing vio-
lations.
To find out the number of flash wait states required,
divide the core clock frequency (in MHz) by 20 and take
the integer part of the result. The value that is written
to PFMWS (CHECON<2:0>) is one less. For example,
core clock frequency is 72MHZ. The number of wait
states will be 72 / 20 = 3.6, i.e., 3 wait states. Therefore
the actual value written to PFMWS bits will be 2.
© 2007 Microchip Technology Inc.
Program Flash Memory Wait
States
Advance Information
6.6
The Program Flash Memory can be partitioned for User
and Kernel mode programs as shown in Figure 6-3.
At Reset, the User mode partition does not exist (BMX-
PUPBA is initialized to ‘0’). The entire Program Flash
Memory is mapped to Kernel mode program space
starting at virtual address KSEG1: 0xBD000000 (or
KSEG0: 0x9D000000). To set up a partition for the
User mode program, initialize BMXPUPBA as follows:
BMXPUPBA = BMXPFMSZ – USER_FLASH_PGM_SZ
The USER_FLASH_PGM_SZ is the partition size of
the User mode program. BMXPFMSZ is the bus matrix
register that holds the total size of Program Flash
Memory.
Example:
The size of the user Flash will be 20K and the size left
for the kernel Flash will be 512k – 20k = 492K.
The user Flash partition will extend from 0x7D07B000
to 0x7d07FFFF (virtual addresses).
The Kernel mode partition always starts from KSEG1:
0xBD000000 or KSEG0: 0x9D000000. In the above
example, the kernel partition will extend from
0xBD000000 to 0xBD07AFFF (492 Kbytes in size).
Assuming the PIC32MX device has 512 Kbytes of
Flash memory, the BMXPFMSZ will contain
0x00080000.
To create a user Flash program partition of
20 Kbytes (0x5000):
BMXPUPBA = 0x80000 – 0x5000 = 0x7B000
PIC32MX FAMILY
Program Flash Memory
Partitioning
DS61143A-page 119

Related parts for pic32mx320f064h