User manual

Rev. 1.00, 05/04, page 300 of 544
Bit Bit Name
Initial
Value R/W Description
0 ACKB 0 R/W Acknowledge Bit
Stores acknowledge data.
Transmit mode:
[Setting condition]
When 1 is received as the acknowledge bit when ACKE
= 1 in transmit mode
[Clearing conditions]
• When 0 is received as the acknowledge bit when
ACKE = 1 in transmit mode
• When 0 is written to the ACKE bit
Receive mode:
0: Returns 0 as acknowledge data after data reception
1: Returns 1 as acknowledge data after data reception
When this bit is read, the value loaded from the bus line
(returned by the receiving device) is read in
transmission (when TRS = 1). In reception (when TRS
= 0), the value set by internal software is read.
When this bit is written, acknowledge data that is
returned after receiving is rewritten regardless of the
TRS value. If bit in ICSR is written using bit-
manipulation instructions, the acknowledge data should
be re-set since the acknowledge data setting is
rewritten by the ACKB bit reading value.
Write the ACKE bit to 0 to clear the ACKB flag to 0,
before transmission is ended and a stop condition is
issued in master mode, or before transmission is ended
and SDA is released to issue a stop condition by a
master device.
Note: * Only 0 can be written to clear the flag.