eeprom: control logic: define instructions layout and write out script

1 files changed, 98 insertions, 0 deletions

diff --git a/write_inst_eeprom.py b/write_inst_eeprom.py
new file mode 100644
index 0000000..224572a
--- /dev/null
+++ b/write_inst_eeprom.py
@@ -0,0 +1,98 @@
+## This file writes the in inst.py defined instruction to the AT28C EEPROM 
+## conntected to a raspberry pi via GPIO pins
+
+import inst
+import eeprom_pi as ep
+
+## for cmd line args access
+import sys
+
+## given an address and an instruction this writes corredsponding bytes to the 
+## EEPROM
+def write_micro_inst_out(address, instruction):
+	ctl_word_half = 0x00
+	if eeprom_n == 1:
+		ctl_word_half = instruction & 0xff
+	elif eeprom_n == 2:
+		ctl_word_half = (instruction >> 8) & 0xff
+
+	print("%s: %s (%s)" % (hex(address), hex(ctl_word_half), 
+		hex(instruction)))
+	ep.write_data_at(address, ctl_word_half)
+
+
+
+## look for cmd line parameter to known which EEPROM we write to currently
+if(len(sys.argv) != 2):
+	print("usage: %s <number eeprom>" % sys.argv[0])
+	print("please specify the eeprom you want to write to.")
+	exit()
+
+eeprom_n = int(sys.argv[1])
+
+if not (eeprom_n == 1 or eeprom_n == 2):
+	print("error: only two eeproms supported right now")
+	exit()
+
+print("writing eeprom %s" % eeprom_n)
+
+## setup board
+ep.init_board()
+
+
+## for every instruction
+nr_inst = 1
+for instruction_data in inst.INST:
+	print("writing instruction %s" % nr_inst)
+	base_address = instruction_data[0]
+	mops = instruction_data[1]
+	n = 0
+
+	# write fetch instruction micro ops for every instruction
+	for fi_mop in inst.INST_MICRO_OP_FETCH_INSTRUCTION:
+		write_micro_inst_out(base_address+n, fi_mop)
+		n += 1
+
+	print("------------")
+
+	for mop in mops:
+		write_micro_inst_out(base_address+n, mop)
+		n += 1
+
+	## insert 0x00 for not used micro instuctions, so all control signals 0
+	## and the pc is not doing some unwanted stuff
+	while n < inst.MAX_MICRO_OPS:
+		write_micro_inst_out(base_address+n, 0x0000)
+		n += 1
+
+
+	nr_inst += 1
+
+	
+## write a fetch instruction at address 0x0, so that after a reset we are 
+## fetching the first instruction
+print("\n")
+print("writing inst fetch instruction at address 0x0, so we begin executing"
+		"after reset:")
+n = 0
+base_address = 0x0
+for fi_mop in inst.INST_MICRO_OP_FETCH_INSTRUCTION:
+	write_micro_inst_out(base_address+n, fi_mop)
+	n += 1
+
+## write NULLs
+while n < inst.MAX_MICRO_OPS:
+	write_micro_inst_out(base_address+n, 0x0000)
+	n += 1
+
+## write HLT instruction aka, everything 0x00, no new instruction fetch cycle
+n = 0
+base_address = inst.INST_HLT
+while n < inst.MAX_MICRO_OPS:
+	write_micro_inst_out(base_address+n, 0x0000)
+	n += 1
+	
+
+trash = raw_input("please unplug the power to the EEPORM now and press any key to continue...")
+
+ep.cleanup()