7.2.2 Inputs and Outputs Signals

The following table lists the input and output ports of T-Format Interface.

Table 7-6. Inputs and Outputs of T-Format Interface
Signal Name	Direction	Description
reset_i	Input	Active low asynchronous reset signal to design
sys_clk_i	Input	System Clock
ref_clk_i	Input	Reference clock, 2.5MHz*
start_i	Input	Startsignal to start T-Format transaction – must be ‘1’ for one sys_clk_i cycle
alarm_clr_i	Input	Clearalarm signal – must be ‘1’ for one sys_clk_i cycle
rx_i	Input	Serialdata input from encoder
crc_done_i	Input	Donesignal from external CRC block –must be ‘1’ for one sys_clk_i cycle
cmd_i	Input	ControlField ID to be sent to encoder
crc_calc_i	Input	Outputof CRC Generator block with bits reversed, that is, crc_gen(7) -> crc_calc_i (0), crc_gen(6)-> crc_calc_i(1), .. crc_gen(0)-> crc_calc_i(7)
tx_o	Output	Serial data output to encoder
tx_en_o	Output	Transmit enable signal – goes high when transmission is in progress
done_o	Output	Transaction done signal – asserted as a pulse with a width of one sys_clk_i cycle
alarm_o	Output	Alarm signal – asserted when the number of fault occurrences equals the threshold value configured in g_FAULT_THRESHOLD
start_crc_o	Output	Start signal for CRC generation block
data_crc_o	Output	Datafor CRC generation block – data is provided as: {CF, SF, D0, D1, D2, .. D7} without delimiters. In case of shorter messages (where only D0-D2 have data), the other fields D3-D7 are taken as 0
tf_error_o	Output	TF Error register
id_o	Output	ID value from control field in received frame*
sf_o	Output	Status field from received frame*
d0_o	Output	D0field from received frame*
d1_o	Output	D1field from received frame*
d2_o	Output	D2field from received frame*
d3_o	Output	D3field from received frame*
d4_o	Output	D4field from received frame*
d5_o	Output	D5field from received frame*
d6_o	Output	D6field from received frame*
d7_o	Output	D7field from received frame*
crc_o	Output	CRC field from received frame*

Note: For more information, see the Tamagawa datasheet.