HD64570 HITACHI [Hitachi Semiconductor], HD64570 Datasheet - Page 157

• Manufacturer Part Number: HD64570
• Description: Serial Communications Adaptor
• Manufacturer: HITACHI [Hitachi Semiconductor]

Bit 6 (PMP/SHRT: Parity/MP Bit/Short Frame): Indicates the parity/MP bit value in
asynchronous mode, or short frame detection in bit synchronous mode. This bit is cleared when 1
is written to this bit position.
Bit 5 (PE/ABT: Parity Error/Abort End Frame): Indicates detection of a parity error in
asynchronous mode, or an abort end frame in bit synchronous mode.
This bit is cleared when 1 is written to this bit position.
EOM = 0:
EOM = 1:
Asynchronous mode
The PMP bit indicates the status of the parity bit, MP bit, or receive character MSB according
PMPM1 PMPM0: to the condition: indicates parity bit status when mode register 1's (MD1)
PMPM1 PMPM0 bits are 10 or 11; indicates MP bit status when MD1's PMPM1 PMPM0
bits are 01; and indicates receive character MSB status when MD1's PMPM1 PMPM0 bits
are 00.
The PMP bit is updated when the next receive character is ready to be read.
PMP = 0:
PMP = 1:
Byte synchronous mode
Reserved. This bit always reads 0 and can be set to 0 or 1.
Bit synchronous mode
The SHRT bit indicates short frame detection. When the CRCCC bit of MD0 is 1, this bit is
set to 1 by the last character in the I field if the receive frame is short and a part of the data is
sent to the receive buffer. When the CRCCC bit is 0, this bit is set to 1 by the last character of
FCS.
However, even when the receive frame is short, this bit is not set to 1 if no data is sent to the
receive buffer.
When the SHRT bit is set to 1, the EOM bit is also set to 1.
For details, see Short Frame Detection, in section 5.3.3, Bit Synchronous Mode.
SHRT = 0:
SHRT = 1:
sent to the receive buffer
Asynchronous mode
PE = 0:
PE = 1:
Once set to 1, this bit is not cleared until the receiver is reset or 1 is written to this bit position.
Byte synchronous mode
Indicates that the receive frame has not ended
Indicates that the receive frame has ended
Indicates that the parity bit, MP bit, or receive character MSB is 0
Indicates that the parity bit, MP bit, or receive character MSB is 1
Indicates that no short frame has been detected
Indicates that a short frame has been detected and that a part of the data has been
Indicates that no parity error has occurred
Indicates that a parity error has occurred
Rev. 0, 07/98, page 141 of 453