C8051F340/1/2/3/4/5/6/7
Table 17.3. Sources for Hardware Changes to SMB0CN
Bit | Set by Hardware When: | Cleared by Hardware When: | |
MASTER | • A START is generated. | • A STOP is generated. | |
| • Arbitration is lost. | ||
|
| ||
| • START is generated. | • A START is detected. | |
TXMODE | • SMB0DAT is written before the start of an | • Arbitration is lost. | |
SMBus frame. | • SMB0DAT is not written before the | ||
| |||
|
| start of an SMBus frame. | |
STA | • A START followed by an address byte is | • Must be cleared by software. | |
received. |
| ||
|
| ||
STO | • A STOP is detected while addressed as a | • A pending STOP is generated. | |
slave. |
| ||
| • Arbitration is lost due to a detected STOP. |
| |
ACKRQ | • A byte has been received and an ACK | • After each ACK cycle. | |
response value is needed. |
| ||
|
| ||
| • A repeated START is detected as a MASTER | • Each time SI is cleared. | |
| when STA is low (unwanted repeated START). |
| |
ARBLOST | • SCL is sensed low while attempting to gener- |
| |
ate a STOP or repeated START condition. |
| ||
|
| ||
| • SDA is sensed low while transmitting a ‘1’ |
| |
| (excluding ACK bits). |
| |
ACK | • The incoming ACK value is low (ACKNOWL- | • The incoming ACK value is high (NOT | |
EDGE). | ACKNOWLEDGE). | ||
| |||
| • A START has been generated. | • Must be cleared by software. | |
| • Lost arbitration. |
| |
| • A byte has been transmitted and an ACK/ |
| |
SI | NACK received. |
| |
• A byte has been received. |
| ||
|
| ||
| • A START or repeated START followed by a |
| |
| slave address + R/W has been received. |
| |
| • A STOP has been received. |
|
Rev. 0.5 | 203 |