Serial chain loading of the I/O configurations is now working.
diff --git a/verilog/rtl/gpio_control_block.v b/verilog/rtl/gpio_control_block.v
index 2325b39..5d3adb1 100644
--- a/verilog/rtl/gpio_control_block.v
+++ b/verilog/rtl/gpio_control_block.v
@@ -1,17 +1,13 @@
/*
*---------------------------------------------------------------------
- * This block interfaces between the sky130_fd_io GPIOv2 pad, the
- * caravel management area, and the user project area.
- *
- * The management area has ultimate control over the setting of the
- * pad, and can modify all core-voltage inputs to the pad and monitor
- * the output.
- *
- * The user project will rely on the management SoC startup program
- * to configure each I/O pad to a fixed configuration except for
- * the output enable which remains under user control.
- *
- * This module is bit-sliced. Instantiate once for each GPIO pad.
+ * See gpio_control_block for description. This module is like
+ * gpio_contro_block except that it has an additional two management-
+ * Soc-facing pins, which are the out_enb line and the output line.
+ * If the chip is configured for output with the oeb control
+ * register = 1, then the oeb line is controlled by the additional
+ * signal from the management SoC. If the oeb control register = 0,
+ * then the output is disabled completely. The "io" line is input
+ * only in this module.
*
*---------------------------------------------------------------------
*/
@@ -51,7 +47,9 @@
input resetn, // Global reset
input serial_clock,
- inout mgmt_gpio_io, // Management to/from pad
+ output mgmt_gpio_in, // Management from pad (input only)
+ input mgmt_gpio_out, // Management to pad (output only)
+ input mgmt_gpio_oeb, // Management to pad (output only)
// Serial data chain for pad configuration
input serial_data_in,
@@ -72,7 +70,7 @@
output pad_gpio_ana_sel,
output pad_gpio_ana_pol,
output [2:0] pad_gpio_dm,
- output pad_gpio_oeb,
+ output pad_gpio_outenb,
output pad_gpio_out,
input pad_gpio_in
);
@@ -81,7 +79,7 @@
localparam MGMT_EN = 0;
localparam OEB = 1;
localparam HLDH = 2;
- localparam INP_DIS = 2;
+ localparam INP_DIS = 3;
localparam MOD_SEL = 4;
localparam AN_EN = 5;
localparam AN_SEL = 6;
@@ -148,7 +146,7 @@
gpio_vtrip_sel <= TRIP_INIT; // CMOS mode
gpio_ib_mode_sel <= IB_INIT; // CMOS mode
gpio_inenb <= IENB_INIT; // Input enabled
- gpio_outenb <= OENB_INIT; // Output disabled
+ gpio_outenb <= OENB_INIT; // (unused placeholder)
gpio_dm <= DM_INIT; // Configured as input only
gpio_ana_en <= AENA_INIT; // Digital enabled
gpio_ana_sel <= ASEL_INIT; // Don't-care when gpio_ana_en = 0
@@ -185,34 +183,10 @@
/* Implement pad control behavior depending on state of mgmt_ena */
- /* If pad is configured for input and dm[2:1] is 01, then pad is */
- /* configured as pull-up or pull-down depending on dm[0], and to */
- /* set the pullup or pulldown condition, the pad output bit must */
- /* be set to the opposite state of dm[0]. */
- /* dm[0] = 0 is pull-down; dm[0] = 1 is pull-up. */
- /* */
- /* This is done for management control only, since the management */
- /* control has only 1 inout signal for both input and output, and */
- /* cannot set the output and read the input simultaneously. The */
- /* user has control over both lines and only needs to be told what */
- /* to set the output line to, to enable a pullup or pulldown. */
+ assign pad_gpio_out = (mgmt_ena) ? mgmt_gpio_out : user_gpio_out;
+ assign pad_gpio_outenb = (mgmt_ena) ? mgmt_gpio_oeb : user_gpio_oeb;
- assign pad_gpio_out = (mgmt_ena) ?
- (((gpio_dm[2:1] == 2'b01) && (gpio_inenb == 1'b0)) ?
- ~gpio_dm[0] : mgmt_gpio_io) : user_gpio_out;
-
- /* When under user control, gpio_outenb = 1 means that the pad is */
- /* configured as input, and the user outenb is unused. Otherwise, */
- /* the pad outenb signal is controlled by the user. */
-
- assign pad_gpio_outenb = (mgmt_ena) ? gpio_outenb :
- ((gpio_outenb == 1) ? 1'b1 : user_gpio_oeb);
-
- /* User gpio_in is grounded when the management controls the pad */
- assign user_gpio_in = (mgmt_ena) ? 1'b0 : pad_gpio_in;
-
- /* Management I/O line is set from the pad when the pad is */
- /* configured for input. */
- assign mgmt_gpio_io = (gpio_inenb == 0) ? pad_gpio_in : 1'bz;
+ assign user_gpio_in = (mgmt_ena) ? 1'b0 : pad_gpio_in;
+ assign mgmt_gpio_in = (mgmt_ena) ? pad_gpio_in : 1'b0;
endmodule
