APPENDIX D BOOT
AP-D-6
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
PC RS232C Boot
D.4
Configuration of PC RS232C Boot System
D.4.1
When the S1C33L26 is turned on or reset with the BOOT pin set to 1 (HV
DD
) and the #CE10 pin set to 0 (V
SS
), the
S1C33L26 boots up by executing the MBR after loading it from the PC (RS232C) to IRAM via FSIO Ch.1.
Figure D.4.1.1 shows a PC RS232C boot system connection diagram.
S1C33L26
TXD
RXD
GND
COMx
BOOT
#CE10 (P53)
(P00) SIN1
(P01) SOUT1
V
SS
HV
DD
4.1.1 PC RS232C Boot System
Figure D.
4.1.1 Pins Used for PC RS232C Boot
Table D.
S1C33L26 pin
RS232C pin
Pin status before booting
Pin status after booting
P00/USI_DI/
SIN1/#NAND_WR
TXD
Input
Input
P01/USI_DO/
SOUT1/#NAND_RD
RXD
Input
Output
#CE10/
P53
*
1
–
Input (pulled up internally)
Input
*
1 Used to select SPI-EEPROM boot or PC RS232C boot during boot mode configuration with the BOOT pin.
The pins listed in the table are configured for FSIO Ch.1 (pin names in
boldface
) in the boot sequence. Therefore,
these pins cannot be used for general-purpose I/O or other peripheral functions.
The baud rate and RS232C parameters are configured as below in the boot sequence.
Baud rate:
Automatically detected, 9600 bps typ. (Note)
Data bit length: 8 bits
Start bit:
1 bit
Stop bit:
2 bit
Parity:
None
Note: Table D.4.1.2 shows the maximum baud rate that can be set according to the S1C33L26 system
clock (OSC3) frequency. The baud rate values in the vicinity of maximum frequency may have an
error on the order of 5 percent. Use a lower baud rate to reduce an error.
4.1.2 System Clock Frequency and Baud Rate
Table D.
OSC3 frequency
> 500 kHz
> 4 MHz
> 7 MHz
> 15 MHz
> 29 MHz
> 40 MHz
Maximum baud rate (bps)
1200
9600
19200
38400
57600
115200
PC RS232C Boot Sequence
D.4.2
Figure D.4.2.1 shows the PC RS232C boot flowchart.