link to page 10 link to page 10 link to page 10 link to page 10 link to page 10 MAX30208 ±0.1°C Accurate, I2C Digital Temperature Sensor GPIO The state of GPIO pins at each I2C start condition is used The MAX30208 provides access to two GPIO pins which to determine the last two bits of the I2C address. This use can be used to provide additional functionality. GPIO0 of the GPIO pins is further detailed below in the I2C Slave can be configured to output an interrupt while GPIO1 can Address section. be configured as an input for a temperature conversion. I2C The interrupt on GPIO0 is triggered based on selectable status bits in the INTERRUPT_ENABLE[0x01] register. I2C Slave Address By writing to one of the availabe bits in the INTERRUPT_ I2C Slave Address is 8 bits as shown in Table 3. Bit 0 is 0 ENABLE register, the flag for an interrupt is raised if for a write operation and 1 for a read operation. GPIO0_MODE[1:0] in the GPIO_SETUP [0x20] register is At powerup, GPIO0 and GPIO1 are set to mode 10 as set to 11. When GPIO1_MODE[7:0] in the GPIO_SETUP shown in Table 3. The I2C address is determined by the register is set to 11, driving the line low initiates an exter- state of these pins. If the mode of either of the GPIO nal temperature conversion. Table 2 shows a complete list pins is changed to 01 or 11 then those address pins are of the functions of the two GPIO Pins. automatically pulled low internally and can change the I2C address. Table 2. GPIO Mode FunctionsGPIOX_MODE[1:0] (X = 0, 1)GPIO0GPIO1 00 HiZ Input HiZ Input 01 Output Output 10 (default) 1MΩ Internal Pulldown Input 1MΩ Internal Pulldown Input 11 INTB CONV Table 3. I2C Slave AddressI2C ADDRESSW/RGPIO STATESCONDITION 7 6 5 4 3 2 1 0 GPIO1_GPIO0_MODE[1:0] MODE[1:0] 1 0 1 0 0 GPIO1 GPIO0 0/1 10 10 Default state at powerup 1 0 1 0 0 GPIO1 GPIO0 0/1 00 00 Both GPIO1 and GPIO0 are inputs 1 0 1 0 0 GPIO1 GPIO0 0/1 10 00 Both GPIO1 and GPIO0 are inputs 1 0 1 0 0 GPIO1 GPIO0 0/1 00 10 Both GPIO1 and GPIO0 are inputs 1 0 1 0 0 GPIO1 0 0/1 00 01 GPIO1 is an input, GPIO0 is an output 1 0 1 0 0 GPIO1 0 0/1 00 11 GPIO1 is an input, GPIO0 is an output 1 0 1 0 0 GPIO1 0 0/1 10 01 GPIO1 is an input, GPIO0 is an output 1 0 1 0 0 GPIO1 0 0/1 10 11 GPIO1 is an input, GPIO0 is an output 1 0 1 0 0 0 GPIO0 0/1 01 00 GPIO1 is an output, GPIO0 is an input 1 0 1 0 0 0 GPIO0 0/1 01 10 GPIO1 is an output, GPIO0 is an input 1 0 1 0 0 0 GPIO0 0/1 11 00 GPIO1 is an output, GPIO0 is an input 1 0 1 0 0 0 GPIO0 0/1 11 10 GPIO1 is an output, GPIO0 is an input 1 0 1 0 0 0 0 0/1 01 01 GPIO1 and GPIO0 are outputs 1 0 1 0 0 0 0 0/1 01 11 GPIO1 and GPIO0 are outputs 1 0 1 0 0 0 0 0/1 11 01 GPIO1 and GPIO0 are outputs 1 0 1 0 0 0 0 0/1 11 11 GPIO1 and GPIO0 are outputs www.maximintegrated.com Maxim Integrated │ 10