EZ80F91MCU Datasheet, PDF (251/396 Pages) Zilog, Inc. – eZ80Acclaim-TM Flash Microcontrollers

eZ80F91 MCU
Product Specification
232
Software Reset. Perform a software reset by writing any value to the I²C Software
Reset Register (I2C_SRR). A software reset clears the STP, STA, and IFLG bits of
the I2C_CTL register to 0 and sets the I²C back to an idle state.
I²C Slave Address Register
The I2C_SAR register provides the 7-bit address of the I²C when in SLAVE mode
and allows 10-bit addressing in conjunction with the I2C_XSAR register.
I2C_SAR[7:1] = SLA[6:0] is the 7-bit address of the I²C when in 7-bit SLAVE
mode. When the I²C receives this address after a START condition, it enters
SLAVE mode. I2C_SAR[7] corresponds to the first bit received from the I²C bus.
When the register receives an address starting with F7h to F0h (I2C_SAR[7:3] =
11110b), the I²C recognizes that a 10-bit slave addressing mode is being selected.
The I²C sends an ACK after receiving the I2C_SAR byte (the device does not
generate an interrupt at this point). After the next byte of the address (I2C_XSAR)
is received, the I²C generates an interrupt and enters SLAVE mode.Then
I2C_SAR[2:1] are used as the upper 2 bits for the 10-bit extended address. The
full 10-bit address is supplied by {I2C_SAR[2:1], I2C_XSAR[7:0]}. See Table 124.
Table 124. I²C Slave Address Register
(I2C_SAR = 00C8h)
Bit
Reset
CPU Access
Note: R/W = Read/Write.
7
0
R/W
6
0
R/W
5
0
R/W
4
0
R/W
3
0
R/W
2
0
R/W
1
0
R/W
0
0
R/W
Bit
Position
[7:1]
SLA
0
GCE
Value Description
00h–
7Fh
0
1
7-bit slave address or upper 2 bits,I2C_SAR[2:1], of address
when operating in 10-bit mode.
I²C not enabled to recognize the General Call Address.
I²C enabled to recognize the General Call Address.
I²C Extended Slave Address Register
The I2C_XSAR register is used in conjunction with the I2C_SAR register to pro-
vide 10-bit addressing of the I²C when in SLAVE mode. The I2C_SAR value
forms the lower 8 bits of the 10-bit slave address. The full 10-bit address is sup-
plied by {I2C_SAR[2:1], I2C_XSAR[7:0]}.
When the register receives an address starting with F7h to F0h (I2C_SAR[7:3] =
11110b), the I²C recognizes that a 10-bit slave addressing mode is being selected.
PS019209-0504
PRELIMINARY
I²C Serial I/O Interface