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JN-DS-JN5142 1v0
© NXP Laboratories UK 2012
4 Memory Organisation
This section describes the different memories found within the JN5142. The device contains ROM, RAM, OTP eFuse
memory, the wireless transceiver and peripherals all within the same linear address space.
0x00000000
0x00020000
RAM
(32KB)
0xF0000000
0xFFFFFFFF
Unpopulated
ROM
(128KB)
0xF0008000
RAM Echo
0x04000000
Peripherals
0x02000000
Figure 5: JN5142 Memory Map
4.1 ROM
The ROM is 128k bytes in size, and can be accessed by the processor in a single CPU clock cycle. The ROM
contents include bootloader to allow external Flash memory contents to be bootloaded into RAM at runtime, a default
interrupt vector table, an interrupt manager, IEEE802.15.4 MAC and APIs for interfacing on-chip peripherals. The
operation of the boot loader is described in detail in Application Note [9]. The interrupt manager routes interrupt calls
to the application‟s soft interrupt vector table contained within RAM. Section 7 contains further information regarding
the handling of interrupts. ROM contents are shown in Figure 6.
Interrupt Vectors
Interrupt Manager
Boot Loader
IEEE802.15.4
Stack
0x00000000
0x00020000
APIs
Spare
Network Stack
Figure 6: Typical ROM Contents