Special Mode 3 (Ie Mode) - Renesas M16C/6NK Hardware Manual

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M16C/6N Group (M16C/6NK, M16C/6NM)

15.1.5 Special Mode 3 (IE Mode)

In this mode, one bit of IEBus is approximated with one byte of UART mode waveform.
Table 15.16 lists the registers used in IE mode and the register values set. Figure 15.31 shows the
functions of bus collision detect function related bits.
If the TXDi pin (i = 0 to 2) output level and RXDi pin input level do not match, a UARTi bus collision detect
interrupt request is generated.
Use the IFSR06 and IFSR07 bits in the IFSR0 register to enable the UART0/UART1 bus collision detect function.
Table 15.16 Registers to Be Used and Settings in IE Mode
Register Bit
UiTB 0 to 8
(1)
UiRB 0 to 8
OER,FER,PER,SUM
UiBRG 0 to 7
UiMR SMD2 to SMD0
CKDIR
STPS
PRY
PRYE
IOPOL
UiC0 CLK1, CLK0
CRS
TXEPT
CRD
NCH
CKPOL
UFORM
UiC1 TE
TI
RE
RI
(2)
U2IRS
(2)
U2RRM
UiLCH, UiERE
UiSMR 0 to 3, 7
ABSCS
ACSE
SSS
UiSMR2 0 to 7
UiSMR3 0 to 7
UiSMR4 0 to 7
IFSR0 IFSR06, IFSR07
UCON U0IRS, U1IRS
U0RRM, U1RRM
CLKMD0
CLKMD1, RCSP, 7
i= 0 to 2
NOTES:
1. Not all register bits are described above. Set those bits to "0" when writing to the registers in IE mode.
2. Set the bit 4 and bit 5 in the U0C1 and U1C1 registers to "0". The U0IRS, U1IRS, U0RRM and U1RRM
bits are in the UCON register.
Rev.2.00 Nov 28, 2005
REJ09B0124-0200
Set transmission data
Reception data can be read
Error flag
Set a transfer rate
Set to "110b"
Select the internal clock or external clock
Set to "0"
Invalid because the PRYE bit = 0
Set to "0"
Select the TXD/RXD input/output polarity
Select the count source for the UiBRG register
Invalid because the CRD bit = 1
Transmit register empty flag
Set to "1"
Select TXDi pin output mode
Set to "0"
Set to "0"
Set this bit to "1" to enable transmission
Transmit buffer empty flag
Set this bit to "1" to enable reception
Reception complete flag
Select the source of UART2 transmit interrupt
, Set to "0"
Set to "0"
Select the sampling timing at which to detect a bus collision
Set this bit to "1" to use the auto clear function of transmit enable bit
Select the transmit start condition
Set to "0"
Set to "0"
Set to "0"
Set to "1"
Select the source of UART0/UART1 transmit interrupt
Set to "0"
Invalid because the CLKMD1 bit = 0
Set to "0"
page 189 of 378
Function
15. Serial Interface