Technical information

CSI to SPI Peripheral Communication in V850ES Microcontrollers

After processing the switches, main() returns to the top of the program loop to check switch states

again.

2.6.3 Temp_Init(): Initialize Temperature Sensor Interface

The Temp_Init() routine initializes the temperature sensors to prepare them for reading.

Temp_Init() first sets the chip selects for the two temperature sensors to the inactive state, and then

calls CSI00_Init() to initialize the clocked serial interface 00 for operation.

For the MAX6627 temperature sensor (TEMP1), temperature conversions are done once per

second, and the most recent conversion is available for reading at any time. No further initialization

is necessary.

For the DS1722 temperature sensor (TEMP2), the default power-up state is for 8-bit resolution (to

the nearest 1ºC), and to enter power-down mode. To program the device for 10-bit resolution and

for continuous conversion, the Configuration register must be set.

Figure 13. Temp_Init(): Initialize Temperature Sensor Interface

Yes

SendDone

== FALSE?

Yes

SendDone

== FALSE?

CALL CSI00_Init( )CALL CSI00_Init( )

Return

CALL CSI00_SetType3( )

TEMP2_CS_ON (P9H.6 = 1)

CALL CSI00_SetType3( )

TEMP2_CS_ON (P9H.6 = 1)

txbuf[0] = 0x80

txbuf[1] = 0xE4

txbuf[0] = 0x80

txbuf[1] = 0xE4

CSI00_SendDone = FALSE

CALL CSI00_SendData(txbuf, 2)

CSI00_SendDone = FALSE

CALL CSI00_SendData(txbuf, 2)

Delay 400ns from CS onDelay 400ns from CS on

TEMP1_CS_OFF (P9H.7 = 1)

TEMP2_CS_OFF (P9H.6 = 0)

TEMP1_CS_OFF (P9H.7 = 1)

TEMP2_CS_OFF (P9H.6 = 0)

TEMP2_CS_OFF (P9H.6 = 0)TEMP2_CS_OFF (P9H.6 = 0)