diff options
author | 2015-03-19 02:08:31 -0400 | |
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committer | 2015-03-19 02:08:31 -0400 | |
commit | 0c58c7212c5d52b9bd94191b328177c426d39495 (patch) | |
tree | dae83bb862c755bb7b25390b7d7d06dc701b8e1b | |
parent | 1477c0133e5bc6883df9cfdb35a325e9d9d13e4b (diff) |
(MESS) upd1771.c - notes update, indicate what pins are inputs, outputs, or both; document the d/a power pin. document the mode pin functions and the test mode [kevtris]
-rw-r--r-- | src/mess/audio/upd1771.c | 40 |
1 files changed, 23 insertions, 17 deletions
diff --git a/src/mess/audio/upd1771.c b/src/mess/audio/upd1771.c index 4db60193920..bac1b853c14 100644 --- a/src/mess/audio/upd1771.c +++ b/src/mess/audio/upd1771.c @@ -108,30 +108,36 @@ 6Mhz XIN 9 20 D2 6Mhz XOUT 10 19 D1 AUDOUT 11 18 D0 - NC 12 17 GND + NC(recheck!)12 17 GND AUDOUT(inv) 13 16 VCC GND 14 15 ? tied to pin 16 (VCC) through a resistor (pullup?) Pinout based on guesses and information in "Electronic Speech Synthesis" by Geoff Bristow (ISBN 0-07-007912-9, pages 148-152), and the data on page 233 of the Nec APC technical manual at http://bitsavers.trailing-edge.com/pdf/nec/APC/819-000100-1003_APC_System_Reference_Guide_Apr83.pdf + I/O pin purpose based on testing by kevtris. [x] is unsure: - PB3 1 28 PB2 - PB4(/ALE) 2 27 PB1 - PB5(/RD) 3 26 PB0 - PB6(/WR) 4 25 D7(PA7) - PB7(/CS) 5 24 D6(PA6) - /RESET 6 23 D5(PA5) - [TEST?] 7 22 D4(PA4) - VCC 8 21 D3(PA3) - XI(CLK) 9 20 D2(PA2) - XO 10 19 D1(PA1) - D/A OUT + 11 18 D0(PA0) - [D/A VREF] 12 17 CH2 - D/A OUT - 13 16 /EXTINT - GND 14 15 CH1 tied to pin 16 (VCC) through a resistor, on APC to VCC thru a 12k resistor and thru a 10uf cap to gnd - - CH1 and CH2 are some sort of mode selects? + PB3 <> 1 28 <> PB2 + PB4(/ALE) <> 2 27 <> PB1 + PB5(/RD) <> 3 26 <> PB0 + PB6(/WR) <> 4 25 <> D7(PA7) + PB7(/CS) <> 5 24 <> D6(PA6) + /RESET -> 6 23 <> D5(PA5) + [/TSTOUT?] <- 7 22 <> D4(PA4) + VCC -- 8 21 <> D3(PA3) + XI(CLK) -> 9 20 <> D2(PA2) + XO <- 10 19 <> D1(PA1) + D/A OUT + <- 11 18 <> D0(PA0) + D/A POWER -- 12 17 <- CH2 + D/A OUT - <- 13 16 <> /EXTINT and [/TSTOUT2?] (test out is related to pin 15 state) + GND -- 14 15 <- CH1 tied to pin 16 (VCC) through a resistor, on APC to VCC thru a 12k resistor and thru a 10uf cap to gnd + + CH1 and CH2 are mode selects, purpose based on testing by kevtris: + CH1 CH2 + H L - 'master' mode, pb4-pb7 are i/o? /EXTINT is an input + L L - 'slave' mode where pb4-pb7 are /ale /rd /wr /cs? /EXTINT may be an output in this mode? + X H - test mode: the 512 byte 16-bit wide ROM is output sequentially on pins pa7-pa0 and pb7-pb0 for the high and low bytes of each word respectively + D/A POWER is the FET source for the D/A OUT+ and D/A OUT- push-pull dac drains; it should be tied to VCC or thereabouts In the SCV (info from plgDavid): pin 5 is tied to the !SCPU pin on the Epoch TV chip pin 29 (0x3600 writes) |