
W83977EF/ CTF
PRELIMINARY
Publication Release Date: March 1999
-106 -
Revision A1
CRF0 (Default 0x00)
Bit 7 - 4: Reserved.
Bit 3: RXW4C
= 0
= 1
Bit 2: TXW4C
= 0
= 1
No reception delay when SIR is changed from TX mode to RX mode.
Reception delays 4 characters-time (40 bit-time) when SIR is changed from TX mode
to RX mode.
No transmission delay when SIR is changed from RX mode to TX mode.
Transmission delays 4 characters-time (40 bit-time) when SIR is changed from RX
mode to TX mode.
Bit 1 - 0: SUBCLKB1, SUBCLKB0
= 00 UART B clock source is 1.8462 Mhz (24MHz/13)
= 01 UART B clock source is 2 Mhz (24MHz/12)
= 10 UART B clock source is 24 Mhz (24MHz/1)
= 11 UART B clock source is 14.769 Mhz (24MHz/1.625)
CRF1 (Default 0x00)
Bit 7: Reserved.
Bit 6: IRLOCSEL. IR I/O pins' location select.
= 0
Through SINB/SOUTB.
= 1
Through IRRX/IRTX.
Bit 5: IRMODE2. IR function mode selection bit 2.
Bit 4: IRMODE1. IR function mode selection bit 1.
Bit 3: IRMODE0. IR function mode selection bit 0.
IR MODE
IR FUNCTION
IRTX
IRRX
00X
Disable
tri-state
high
010*
IrDA
Active pulse 1.6
μ
S
Active pulse 3/16 bit time
Demodulation into SINB/IRRX
011*
IrDA
Demodulation into SINB/IRRX
100
ASK-IR
Inverting IRTX/SOUTB pin
routed to SINB/IRRX
101
ASK-IR
Inverting IRTX/SOUTB & 500
KHZ clock
routed to SINB/IRRX
110
ASK-IR
Inverting IRTX/SOUTB
Demodulation into SINB/IRRX
111*
ASK-IR
Inverting IRTX/SOUTB & 500
KHZ clock
Demodulation into SINB/IRRX
Note: The notation is normal mode in the IR function.