Chapter 18 Flash EEPROMXVIII - 12 Onboard Serial Interface Programming ModexOnboard serial writer (YDC MODEL: AF200)xFlash programming connectors or pins for target board.Software requirementsxLoad program installed in the internal flash EEPROMxProgramming algorithm for operating onboard serial writerCautions on onboard serial programmingxPower supply voltage during programming should be within 2.7 V to 3.6 V. If you program outside t h i slimit, reliability of the written data may be damaged.xAlways set the pull-up resistors on the target board so that serial interface communication pins does notbecome floating state. The pull-up resistors are necessary for the Flash EEPROM not to enter theprogramming mode when the serial writer is not connected.xSerial interface I/O pins used for onboard serial programming should be reserved as dedicated pins toprevent other user circuits from communicating with the device. Altenatively, design your target board tobe capable of normal communication with serial writer.x Install the switch that controlls Vpp pin which supplies +5 V during Flash EEPROM programming andsupplies same potential (VDD ) during other operations.18-6 Onboard Serial Programming Mode18-6-1 OverviewThe onboard serial programming mode is primarily used to program the flash EEPROM in devices that arealready installed on a PCB board with internal serial interface.Hardware and software requirementsHardware and software products required for onboard serial programming are as follows.Hardware requirements
