Application Note
4 of 45
001-84858 Rev. *N
2021-03-23
PSoC 4 Programming Using an External Microcontroller (HSSP)
Introduction
•
HSSP:
HSSP refers to the programming of the target device on the board using a host microcontroller. The
target is programmed through the SWD interface. In this application note, HSSP uses a bit-banging
implementation to program the target device. Bit-banging programming refers to the technique in which
programming pins are manipulated using a software code that resides in the host programmer.
•
Differences between bootloading and HSSP
:
In embedded systems, bootloaders are also used to update the
system firmware. Bootloading and HSSP differ in the following key aspects:
−
Bootloaders are used to update the flash memory of the device over a standard communication protocol.
Bootloaders can update only a specific portion of the flash memory, known as the bootloadable area.
−
On the other hand, HSSP supports complete programming of the flash memory in the target device.
−
Bootloaders can use any standard communication interface (such as, USB, I
2
C, SPI, and UART) to update
the firmware, while HSSP uses an SWD or JTAG interface to program the flash. PSoC 4 supports only SWD
interfaces.
