Hi, I am running through the TT flow to (hopefully) get my submission in today. I am getting a "unmapped cells error" and I don't know why. The unmapped cell is "$_ALDFFE_PPP_". I've looked up the issue and the only hing that might have fixed it is trying different SYNTH_STRATEGY parameters in config.tcl which didn't work. github: https://github.com/devin-macy/tt06-riscv32i-spi-wrapper flow error message

[ERROR]: Synthesis failed. There are unmapped cells after synthesis.
[ERROR]: Step 1 (synthesis) failed with error:
-code 1 -level 0 -errorcode NONE -errorinfo {
    while executing
"throw_error"
    (procedure "check_unmapped_cells" line 7)
    invoked from within
"check_unmapped_cells $final_stat_file"
    (procedure "run_synthesis" line 47)
    invoked from within
"run_synthesis"} -errorline 1
[ERROR]: Flow failed.

1-synthesis.errors file

13/15: $0\cmd_error[0:0]
Creating register for signal `\spi_wrapper.\cmd_error' using process `\spi_wrapper.$proc$/work/src/tt_um_riscv_spi_wrapper.sv:165$578'.
Adding SRST signal on $flatten\spi.$procdff$1121 ($dff) from module tt_um_riscv_spi_wrapper (D = $flatten\spi.$procmux$883_Y, Q = \spi.cmd_error, rval = 1'0).
Adding EN signal on $auto$<http://ff.cc:266:slice$1315|ff.cc:266:slice$1315> ($sdff) from module tt_um_riscv_spi_wrapper (D = 1'1, Q = \spi.cmd_error).
ABC: Error: The network is combinational.
Add tt_um_riscv_spi_wrapper/$auto$<http://insbuf.cc:97:execute$37741|insbuf.cc:97:execute$37741>: \spi.cmd_error -> \uo_out [5]

unmapped cell in netlist

sky130_fd_sc_hd__dfxtp_2 _16717_ (
    .CLK(ui_in[0]),
    .D(_01251_),
    .Q(\spi.r_rx_buff[7] )
  );
  \$_ALDFFE_PPP_  \spi.miso_reg  /* _16718_ */ (
    .AD(\spi.r_tx_buff[7] ),
    .C(ui_in[0]),
    .D(_07345_),
    .E(\spi.mode ),
    .L(ui_in[1]),
    .Q(\spi.miso )
  );
  sky130_fd_sc_hd__dfrtp_2 _16719_ (
    .CLK(ui_in[0]),
    .D(_00003_),
    .Q(\spi.rx_bit_count[0] ),
    .RESET_B(_00006_)
  );