HD6432646 Hitachi, HD6432646 Datasheet - Page 562

• Manufacturer Part Number: HD6432646
• Description: (HD64F264x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

Thus the reception margin in asynchronous mode is given by the following formula.
Formula for reception margin in smart card interface mode
M = (0.5 –
Where M: Reception margin (%)
Assuming values of F = 0, D = 0.5 and N = 372 in the above formula, the reception margin
formula is as follows.
When D = 0.5 and F = 0,
Retransfer Operations (Except Block Transfer Mode): Retransfer operations are performed by
the SCI in receive mode and transmit mode as described below.
[1] If an error is found when the received parity bit is checked, the PER bit in SSR is automatically
[2] The RDRF bit in SSR is not set for a frame in which an error has occurred.
[3] If no error is found when the received parity bit is checked, the PER bit in SSR is not set to 1.
[4] If no error is found when the received parity bit is checked, the receive operation is judged to
[5] When a normal frame is received, the pin retains the high-impedance state at the timing for
528
Retransfer operation when SCI is in receive mode
Figure 14-11 illustrates the retransfer operation when the SCI is in receive mode.
set to 1. If the RIE bit in SCR is enabled at this time, an ERI interrupt request is generated. The
PER bit in SSR should be kept cleared to 0 until the next parity bit is sampled.
have been completed normally, and the RDRF flag in SSR is automatically set to 1. If the RIE
bit in SCR is enabled at this time, an RXI interrupt request is generated.
If DTC data transfer by an RXI source is enabled, the contents of RDR can be read
automatically. When the RDR data is read by the DTC, the RDRF flag is automatically cleared
to 0.
error signal transmission.
M = (0.5 – 1/2 372) 100%
N: Ratio of bit rate to clock (N = 32, 64, 372, and 256)
D: Clock duty (D = 0 to 1.0)
L: Frame length (L = 10)
F: Absolute value of clock frequency deviation
= 49.866%
2N
1
) – (L – 0.5) F –
D – 0.5
N
(1 + F
100%