Datasheet

RL78/L12
CHAPTER 31 ELECTRICAL SPECIFICATIONS (G: TA = -40 to +105°C)
R01UH0330EJ0200 Rev.2.00 939
Dec 13, 2013
5. The smaller maximum transfer rate derived by using fMCK/6 or the following expression is the valid maximum
transfer rate.
Expression for calculating the transfer rate when 1.8 V ≤ EV
DD < 3.3 V and 1.6 V ≤ Vb ≤ 2.0 V
Maximum transfer rate =
1
[bps]
{−Cb × Rb × ln (1 −
1.5
Vb
)} × 3
1
Transfer rate × 2
− {−Cb × Rb × ln (1 −
1.5
Vb
)}
Baud rate error (theoretical value) = × 100 [%]
(
1
Transfer rate
) × Number of transferred bits
* This value is the theoretical value of the relative difference between the transmission and reception sides.
6. This value as an example is calculated when the conditions described in the “Conditions” column are met.
Refer to Note 5 above to calculate the maximum transfer rate under conditions of the customer.
Caution Select the TTL input buffer for the RxDq pin and the N-ch open drain output (V
DD tolerance (32- to 52-pin
products)/EV
DD tolerance (64-pin products)) mode for the TxDq pin by using port input mode register g
(PIMg) and port output mode register g (POMg). For V
IH and VIL, see the DC characteristics with TTL
input buffer selected.
UART mode connection diagram (during communication at different potential)
TxDq
RxDq
Rx
Tx
V
b
Rb
User's device
RL78 microcontroller