Microchip Technology DV164039 Data Sheet
Development Board Hardware
2010 Microchip Technology Inc.
DS51911A-page 45
4.4.5.2
EXTERNAL FLASH MEMORY
The PIC24FJ256DA210 Development Board has two external Flash memory devices.
Selection is controlled by jumper JP23. Only one can be enabled at any given time:
Selection is controlled by jumper JP23. Only one can be enabled at any given time:
• 512 Kbyte Parallel Flash (SST39LF400A), connected to the EPMP port.
• 16 Mbits (2 Mbyte) SPI Serial Flash (SST25VF016B).
Flash memory configuration uses the same jumpers and resistors as SRAM configura-
tion (Figure 4-9). An additional jumper, JP23 (callout 1), selects between the serial and
parallel devices.
tion (Figure 4-9). An additional jumper, JP23 (callout 1), selects between the serial and
parallel devices.
FIGURE 4-9:
FLASH MEMORY CONFIGURATION
4.4.5.2.1
Serial Flash Memory
To use the SPI Flash memory, set jumper JP23 to bridge pins 2 and 3 (PMCS2 – SPI).
The microcontroller’s SPI module is used to communicate with the memory device; the
PMCS2 signal is used as the Chip Select signal .
The microcontroller’s SPI module is used to communicate with the memory device; the
PMCS2 signal is used as the Chip Select signal .
4.4.5.2.2
Parallel Flash Memory
Like the SRAM, the on-board parallel Flash memory can be configured to use one of
three memory address ranges (shown in Table 4-8).
three memory address ranges (shown in Table 4-8).
TABLE 4-8:
PARALLEL FLASH MEMORY RANGES
Size
JP11
R63
Active EPMP
Address
Lines
Recommended Part #
256 Kbyte
(default)
Open
Open
PMA<16:0>
SST39LF400A-55-4C-EKE
512 Kbyte
Bridged
Open
PMA<17:0>
1 Mbyte
Bridged
0
PMA<18:0>
SST39VF800A-70-4C-EKE
M
2
3
4
1