deveopmen
Serial I/O
Preliminary Specifications REV.D
Specifications in this manual are tentative and subject to change.
Mitsubishi microcomputers
M16C/80 (100-pin version) group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
125
Figure 1.16.5. Serial I/O-related registers (1)
b7
UARTi bit rate generator
b0
Symbol
U0BRG
U1BRG
U2BRG
U3BRG
U4BRG
Address
0361
16
0369
16
0339
16
0329
16
02F9
16
When reset
Indeterminate
Indeterminate
Indeterminate
Indeterminate
Indeterminate
Function
Assuming that set value = n, BRGi divides the count source by
n + 1
00
16
to FF
16
Values that can be set
W
R
AA
(b7
(b0
b7
b0
UARTi transmit buffer register
Function
Transmit data
Nothing is assigned.
When write, set "0". When read, their contents are indeterminate.
Symbol
U0TB
U1TB
U2TB
U3TB
U4TB
Address
0363
16
, 0362
16
036B
16
, 036A
16
033B
16
, 033A
16
032B
16
, 032A
16
02FB
16
, 02FA
16
When reset
Indeterminate
Indeterminate
Indeterminate
Indeterminate
Indeterminate
W
R
AA
AA
(b15)
b7
Symbol
U0RB
U1RB
U2RB
U3RB
U4RB
Address
0367
16
, 0366
16
036F
16
, 036E
16
032F
16
, 032E
16
032F
16
, 032E
16
02FF
16
, 02FE
16
When reset
Indeterminate
Indeterminate
Indeterminate
Indeterminate
Indeterminate
b0
(b8)
b7
b0
UARTi receive buffer register
OER
FER
SUM
Function
(During UART mode)
Function
(During clock synchronous
serial I/O mode)
Bit name
Bit
symbol
0 : No framing error
1 : Framing error found
0 : No parity error
1 : Parity error found
0 : No error
1 : Error found
Note 1: Bits 15 through 12 are set to “0” when the serial I/O mode select bit (bits 2 to 0 at addresses
0360
16
, 0368
16
, 0338
16
, 0328
16
and 02F8
16
) are set to “000
2
” or the receive enable bit is set to
“0”.
(Bit 15 is set to “0” when bits 14 to 12 all are set to “0”.) Bits 14 and 13 are also set to “0”
when the lower byte of the UARTi receive buffer register (addresses 0366
16
, 036E
16
, 033E
16
,
032E
16
and 02FE
16
) is read out.
Note 2: Arbitration lost detecting flag is allocated to U2RB, U3RB and U4RB and noting but “0” may
be written. Nothing is assigned in bit 11 of U0RB and U1RB. When write, set "0". When read,
the value of this bit is “0”.
Invalid
Invalid
Invalid
PER
Overrun error flag (Note 1)
Framing error flag (Note 1)
Parity error flag (Note 1)
Error sum flag (Note 1)
0 : No overrun error
1 : Overrun error found
0 : No overrun error
1 : Overrun error found
Nothing is assigned.
When write, set "0". When read, the value of these bits is “0”.
Receive data
W
R
Receive data
A
A
A
A
A
A
A
A
ABT
Arbitration lost detecting
flag (Note 2)
Invalid
0 : Not detected
1 : Detected
AA