APPENDIX E SUMMARY OF PRECAUTIONS
S1C33E07 TECHNICAL MANUAL
EPSON
AP-E-7
AP
Notes
When the transmit-enable bit TXENx is set to 0 to disable transmit operations, the transmit data buffer (FIFO)
is cleared (initialized). Similarly, when the receive-enable bit RXENx is set to 0 to disable receive operations,
the receive data buffer (FIFO) is cleared (initialized). Therefore, make sure that the buffer does not contain
any data waiting for transmission or reading before writing 0 to these bits.
During IrDA receive operations, the RZI circuit recognizes low pulses by means of the signal edge (rising
edge when IRRLx = 0; falling edge when IRRLx = 1). Note that noise may cause a malfunction.
IRRLx: Serial I/F Ch.x IrDA I/F Input Logic Inversion Bit in the Serial I/F Ch.x IrDA Register (D2/0x300Bx4)
Serial Peripheral Interface (SPI)
Be sure to use 32-bit access instructions for reading/writing from/to the SPI control registers (0x301700 to
0x30171C). The SPI control registers do not allow reading/writing using 16-bit and 8-bit access instructions.
Do not access the SPI Control Register 1 (0x301708), SPI Control Register 2 (0x30170C), and SPI Wait
Register (0x301710) while the BSYF (D6/0x301714) is set to 1 (during data transfer).
BSYF: Transfer Busy Flag in the SPI Status Register (D6/0x301714)
To prevent malfunctions, write 0x0 to the SPI Interrupt Control Register (0x301718) to disable all the SPI
interrupt requests, before disabling the SPI circuit (before setting ENA (D0/0x301708) to 0).
ENA: SPI Enable Bit in the SPI Control Register 1 (D0/0x301708)
Direction Control Serial Interface (DCSIO)
Be sure to use 32-bit access instructions for reading/writing from/to the DCSIO Data Load Register
(0x301804). Transmit data for Line A and Line B must be written simultaneously.
To prevent malfunctions, write 0x0 to the DCSIO Interrupt Control Register (0x301814) to disable all the
DCSIO interrupt requests, before disabling the DCSIO circuit (before setting DCSIOEN (D0/0x301800) to 0).
DCSIOEN: DCSIO Enable Bit in the DCSIO Control Register (D0/0x301800)
When using the DCSIO ports as input/open-drain output ports (default configuration), be sure to enable the
internal pull-up resistor (refer to Section III.4.4, “Pin Control Registers”) or to connect an external pull-up
resistor to the pin.
Card Interface (CARD)
The interface supports 16-bit PC cards, such as ATA (CF), LAN (Ethernet, wireless), or modem connected as
an I/O card. SRAM cards, etc. are not supported.
Live or hot-line card insertion and removal are not supported. Power must be turned off before inserting or
removing a card. The automatic recognition of cards is also not supported.
DMA, ZV, and CardBus are also not supported.
To accommodate differences in power supply voltage between the PC card (5 V or 3.3 V) and the S1C33E07,
use a buffer IC (e.g., S1C37120).
The ECC generator supports two data organization modes: 512-byte
× 8-bit mode and 256-word × 16-bit
mode. 256-byte
× 8-bit mode is not supported as it is a seldom-used feature.
The card I/O signals must be connected to the D[15:0] pins when using the ECC function.
ECCRST (D0/0x300311) should be set before using the ECC function.
ECCRST: ECC Circuit Reset Bit in the ECC Reset/Ready Register (D0/0x300311)
The ECCEN (D0/0x300312) should be set only while reading or writing card data. It should be disabled
during command input, address input or status reading.
ECCEN: ECC Circuit Enable Bit in the ECC Enable Register (D0/0x300312)