HD6433937 Datasheet, PDF (273/521 Pages) Hitachi Semiconductor – Hardware Manual

Bit 5: Parity enable (PE)
Bit 5 selects whether a parity bit is to be added during transmission and checked during reception
in asynchronous mode. In synchronous mode parity bit addition and checking is not performed,
irrespective of the bit 5 setting.
Bit 5
PE
Description
0
Parity bit addition and checking disabled*²
(initial value)
1
Parity bit addition and checking enabled*^1/*²
Notes: 1. When PE is set to 1, even or odd parity, as designated by bit PM, is added to transmit
data before it is sent, and the received parity bit is checked against the parity
designated by bit PM.
2. For the case where 5-bit data is selected, see table 10-11.
Bit 4: Parity mode (PM)
Bit 4 selects whether even or odd parity is to be used for parity addition and checking. The PM bit
setting is only valid in asynchronous mode when bit PE is set to 1, enabling parity bit addition and
checking. The PM bit setting is invalid in synchronous mode, and in asynchronous mode if parity
bit addition and checking is disabled.
Bit 4
PM
Description
0
Even parity*¹
(initial value)
1
Odd parity*²
Notes: 1. When even parity is selected, a parity bit is added in transmission so that the total
number of 1 bits in the transmit data plus the parity bit is an even number; in reception,
a check is carried out to confirm that the number of 1 bits in the receive data plus the
parity bit is an even number.
2. When odd parity is selected, a parity bit is added in transmission so that the total
number of 1 bits in the transmit data plus the parity bit is an odd number; in reception, a
check is carried out to confirm that the number of 1 bits in the receive data plus the
parity bit is an odd number.
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