R8CSLASH20 datasheet(416/501 Pages) RENESAS

416 / 501 page

R8C/20 Group, R8C/21 Group

19. Flash Memory

Rev.2.00 Aug 27, 2008

Page 400 of 458

REJ09B0250-0200

19.5

Standard Serial I/O Mode

In standard serial I/O mode, the user ROM area can be rewritten while the MCU is mounted on-board by using a

serial programmer which is applicable for the MCU.

There are three types of Standard serial I/O modes:

• Standard serial I/O mode 1 . . . . Clock synchronous serial I/O used to connect with a serial programmer

• Standard serial I/O mode 2 . . . . Clock asynchronous serial I/O used to connect with a serial programmer

• Standard serial I/O mode 3 . . . . Special clock asynchronous serial I/O used to connect with a serial programmer

This MCU uses Standard serial I/O mode 2 and Standard serial I/O mode 3.

Refer to Appendix 2. Connection Examples between Serial Writer and On-Chip Debugging Emulator.

Contact the manufacturer of your serial programmer for serial programmer. Refer to the user’s manual of your

serial programmer for details on how to use it.

Table 19.7 lists the Pin Functions (Flash Memory Standard Serial I/O Mode 2), Table 19.8 lists the Pin Functions

(Flash Memory Standard Serial I/O Mode 3), Figure 19.17 shows Pin Connections for Standard Serial I/O Mode 3.

After processing the pins shown in Table 19.8 and rewriting a flash memory using a writer, apply “H” to the MODE

pin and reset a hardware if a program is operated on the flash memory in single-chip mode.

19.5.1

ID Code Check Function

The ID code check function determines whether the ID codes sent from the serial programmer and those written

in the flash memory match (refer to 19.3 Functions to Prevent Rewriting of Flash Memory).

Table 19.7

Pin Functions (Flash Memory Standard Serial I/O Mode 2)

Name

I/O

Description

VCC,VSS

Power input

Apply the voltage guaranteed for programming and

erasure to the VCC pin and 0 V to the VSS pin.

RESET

Reset input

Reset input pin.

P4_6/XIN

P4_6 input/clock input

Connect a ceramic resonator or crystal oscillator

between the XIN and XOUT pins.

P4_7/XOUT

P4_7 input/clock output

I/O

P0_0 to P0_7

Input port P0