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bog-dan-ro
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ZxR0
ZX Spectrum expansion board base on Raspberry Pi Zero
GNU General Public License v3.0
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How many GPIOs the proxy chip must have?
#2
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bog-dan-ro
opened
6 years ago
bog-dan-ro
commented
6 years ago
EDGE connector (33 to 37 GPIOs):
Address and data (24 GPIOs):
[x] A00-A15
[x] D0-D7
System Control (4 GPIOs):
[x] MREQ
[x] IOREQ
[x] RD
[x] WR
CPU Control (2 to 5 GPIOs):
[x] WAIT
[x] RESET
[x] CLK ?
[x] INT?
[ ] NMI?
BUS Control (3 to 5 GPIOs):
[x] ROMCS
[x] OE (Upper 4)
[x] OE (Lower 15)
[ ] BUSRQ ?
[ ] BUSACK ?
Voltage (2 pins)
[x] +5V
[x] +GND
Communication with RPi0 (4 GPIOs)
SPI ? (4 GPIOs)
[x] SCLK
[x] MOSI
[x] MISO
[x] SS
JTAG Programing? (4 to 5 pins)
[x] TDI
[x] TDO
[x] TCK
[x] TMS
[ ] TRST ?
a chip with 43 to 48 pins will be needed.
EDGE connector (33 to 37 GPIOs):
Address and data (24 GPIOs):
System Control (4 GPIOs):
CPU Control (2 to 5 GPIOs):
BUS Control (3 to 5 GPIOs):
Voltage (2 pins)
Communication with RPi0 (4 GPIOs)
SPI ? (4 GPIOs)
JTAG Programing? (4 to 5 pins)
a chip with 43 to 48 pins will be needed.