UPD78F1502AGK-GAK-AX Datasheet, PDF (853/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 27 FLASH MEMORY
27.4 Connection of Pins on Board
To write the flash memory on-board, connectors that connect the dedicated flash memory programmer must be
provided on the target system. First provide a function that selects the normal operation mode or flash memory
programming mode on the board.
When the flash memory programming mode is set, all the pins not used for programming the flash memory are in the
same status as immediately after reset. Therefore, if the external device does not recognize the state immediately after
reset, the pins must be handled as described below.
27.4.1 FLMD0 pin
(1) In flash memory programming mode
Directly connect this pin to a flash memory programmer when data is written by the flash memory programmer. This
supplies a writing voltage of the VDD level to the FLMD0 pin.
The FLMD0 pin does not have to be pulled down externally because it is internally pulled down by reset. To pull it
down externally, use a resistor of 1 kΩ to 200 kΩ.
(2) In normal operation mode
It is recommended to leave this pin open during normal operation.
The FLMD0 pin must always be kept at the VSS level before reset release but does not have to be pulled down
externally because it is internally pulled down by reset. However, pulling it down must be kept selected (i.e.,
FLMDPUP = “0”, default value) by using bit 7 (FLMDPUP) of the background event control register (BECTL) (see 27.5
(1) Back ground event control register). To pull it down externally, use a resistor of 200 kΩ or smaller.
Self programming and the rewriting of flash memory with the programmer can be prohibited using hardware, by
directly connecting this pin to the VSS pin.
(3) In self programming mode
It is recommended to leave this pin open when using the self programming function. To pull it down externally, use a
resistor of 100 kΩ to 200 kΩ.
In the self programming mode, the setting is switched to pull up in the self programming library.
Figure 27-4. FLMD0 Pin Connection Example
78K0R/Lx3
microcontrollers
FLMD0
Dedicated flash memory programmer
connection pin
R01UH0004EJ0501 Rev.5.01
837
Jun 20, 2011