h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 534

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 16 I
Bit 0—Acknowledge Bit (ACKB): Stores acknowledge data. In transmit mode, after the
receiving device receives data, it returns acknowledge data, and this data is loaded into ACKB. In
receive mode, after data has been received, the acknowledge data set in this bit is sent to the
transmitting device.
When this bit is read, in transmission (when TRS = 1), the value loaded from the bus line
(returned by the receiving device) is read. In reception (when TRS = 0), the value set by internal
software is read.
When this bit is written to, the acknowledge data transmitted at the receipt is rewritten regardless
of the TRS value. The data loaded from the receiving device is retained, therefore take care of
using bit-manipulation instructions.
Bit 0
ACKB
0
1
16.2.7
STCR is an 8-bit readable/writable register that controls register access, the I
mode (when the on-chip IIC option is included), and on-chip flash memory (F-ZTAT versions),
and selects the TCNT input clock source. For details of functions not related to the I
interface, see section 3.2.4, Serial Timer Control Register (STCR), and the descriptions of the
relevant modules. If a module controlled by STCR is not used, do not write 1 to the corresponding
bit.
STCR is initialized to H'00 by a reset and in hardware standby mode.
Bit 7—Reserved: Do not write 1 to this bit.
Rev. 4.00 Jun 06, 2006 page 480 of 1004
REJ09B0301-0400
Bit
Initial value
Read/Write
Serial Timer Control Register (STCR)
Description
Receive mode: 0 is output at acknowledge output timing
Transmit mode: Indicates that the receiving device has acknowledged the data (signal
is 0)
Receive mode: 1 is output at acknowledge output timing
Transmit mode: Indicates that the receiving device has not acknowledged the data
(signal is 1)
2
C Bus Interface [H8S/2138 Group Option]
R/W
—
7
0
IICX1
R/W
6
0
IICX0
R/W
5
0
IICE
R/W
4
0
FLSHE
R/W
3
0
R/W
—
2
0
2
C interface operating
ICKS1
R/W
1
0
(Initial value)
2
C bus
ICKS0
R/W
0
0