C8051T632-GM Silicon Laboratories Inc, C8051T632-GM Datasheet - Page 134
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C8051T632-GM
Manufacturer Part Number
C8051T632-GM
Description
IC MCU 4KB 20PIN QFN
Manufacturer
Silicon Laboratories Inc
Series
C8051T63xr
Specifications of C8051T632-GM
Program Memory Type
OTP
Program Memory Size
4KB (4K x 8)
Package / Case
20-QFN
Core Processor
8051
Core Size
8-Bit
Speed
25MHz
Connectivity
SMBus (2-Wire/I²C), SPI, UART/USART
Peripherals
POR, PWM, Temp Sensor, WDT
Number Of I /o
17
Ram Size
768 x 8
Voltage - Supply (vcc/vdd)
1.8 V ~ 3.6 V
Data Converters
A/D 16x10b; D/A 1x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Processor Series
C8051T6x
Core
8051
Data Bus Width
8 bit
Data Ram Size
768 B
Interface Type
I2C/SPI/UART
Maximum Clock Frequency
25 MHz
Number Of Programmable I/os
17
Number Of Timers
4
Operating Supply Voltage
1.8 V to 3.6 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
PK51, CA51, A51, ULINK2
Development Tools By Supplier
C8051T630DK
Minimum Operating Temperature
- 40 C
On-chip Adc
16-ch x 10-bit
On-chip Dac
16-ch x 10-bit
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
For Use With
336-1464 - KIT DEV FOR C8051T630 FAMILY
Eeprom Size
-
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Other names
336-1460-5
C8051T630/1/2/3/4/5
21.4.2. SMB0CN Control Register
SMB0CN is used to control the interface and to provide status information (see SFR Definition 21.2). The
higher four bits of SMB0CN (MASTER, TXMODE, STA, and STO) form a status vector that can be used to
jump to service routines. MASTER indicates whether a device is the master or slave during the current
transfer. TXMODE indicates whether the device is transmitting or receiving data for the current byte.
STA and STO indicate that a START and/or STOP has been detected or generated since the last SMBus
interrupt. STA and STO are also used to generate START and STOP conditions when operating as a mas-
ter. Writing a 1 to STA will cause the SMBus interface to enter Master Mode and generate a START when
the bus becomes free (STA is not cleared by hardware after the START is generated). Writing a 1 to STO
while in Master Mode will cause the interface to generate a STOP and end the current transfer after the
next ACK cycle. If STO and STA are both set (while in Master Mode), a STOP followed by a START will be
generated.
The ARBLOST bit indicates that the interface has lost an arbitration. This may occur anytime the interface
is transmitting (master or slave). A lost arbitration while operating as a slave indicates a bus error condi-
tion. ARBLOST is cleared by hardware each time SI is cleared.
The SI bit (SMBus Interrupt Flag) is set at the beginning and end of each transfer, after each byte frame, or
when an arbitration is lost; see Table 21.3 for more details.
Important Note About the SI Bit: The SMBus interface is stalled while SI is set; thus SCL is held low, and
the bus is stalled until software clears SI.
21.4.2.1. Software ACK Generation
When the EHACK bit in register SMB0ADM is cleared to 0, the firmware on the device must detect incom-
ing slave addresses and ACK or NACK the slave address and incoming data bytes. As a receiver, writing
the ACK bit defines the outgoing ACK value; as a transmitter, reading the ACK bit indicates the value
received during the last ACK cycle. ACKRQ is set each time a byte is received, indicating that an outgoing
ACK value is needed. When ACKRQ is set, software should write the desired outgoing value to the ACK
bit before clearing SI. A NACK will be generated if software does not write the ACK bit before clearing SI.
SDA will reflect the defined ACK value immediately following a write to the ACK bit; however SCL will
remain low until SI is cleared. If a received slave address is not acknowledged, further slave events will be
ignored until the next START is detected.
21.4.2.2. Hardware ACK Generation
When the EHACK bit in register SMB0ADM is set to 1, automatic slave address recognition and ACK gen-
eration is enabled. More detail about automatic slave address recognition can be found in Section 21.4.3.
As a receiver, the value currently specified by the ACK bit will be automatically sent on the bus during the
ACK cycle of an incoming data byte. As a transmitter, reading the ACK bit indicates the value received on
the last ACK cycle. The ACKRQ bit is not used when hardware ACK generation is enabled. If a received
slave address is NACKed by hardware, further slave events will be ignored until the next START is
detected, and no interrupt will be generated.
Table 21.3 lists all sources for hardware changes to the SMB0CN bits. Refer to Table 21.5 for SMBus sta-
tus decoding using the SMB0CN register.
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Rev. 1.0