Yamaha n8 Service Manual page 126

n8/n12
System management task is started.
As task management data is stored on the SRAM, the program may not work normally if the SRAM is not working normally.
Check that levels at each control line (/CS, data bus, address bus, /MWR, /MRD, LBN, UBN) between the
SSP1 (MAIN) and SRAM are moving.
/CS
Data bus
MMD[0:15]
Address bus
MMA[1:20]
/MWR
/MRD
/LBN
/UBN
System task is started.
The I 2 C is controlled by the E-BUS receive task through the CPLD. Accordingly, the E-BUS micon connected thereto is
controlled.
Check that the "/RES" of the I
DM-A circuit board (n8)/DM-B circuit board (n12): IC111-38 pin
CPLD
DM-A circuit board (n8)/DM-B circuit board (n12): IC115-17 pin
I 2 C
Check that the signal level of the E-/IC(E-PNS2a) is at High.
DM-A circuit board (n8)/DM-B circuit board (n12): IC111-59 pin (3.3 V typ.)
CPLD
DM-A circuit board (n8)/DM-B circuit board (n12): IC120,121-4 pin (5.0 V typ.)
DM-A circuit board (n8)/DM-B circuit board (n12): CN110,111-1 pin (5.0 V typ.)
Check that levels at each control line (/CS6**, data bus, address bus, IRQ) between the SSP1 (MAIN) and
CPLD are moving.
/CS60RD
/CS61WR
/CS62WR
/CS63WR
Data bus
MMD[0:7]
Address bus
MMA[1],[19]
MIRQ
Check that levels at each control line (data bus, address bus) between the SSP1 (MAIN) and the I
moving.
Data bus
MMD[0:7]
Address bus
MMA[1],[2]
Check that levels at each control line (/CE, /RD, /WR, /INT, SDA, SCL) between the CPLD and the I
moving.
/CS6
/CS6WR
/CS6RD
IRQ[3]
SDA
SCL
126
SSP1(MAIN)
DM-A circuit board (n8)/DM-B circuit board (n12): IC107
152 pin
105,106,108-113,115-118,120-122,124 pin
125-128,132-137,139-141,143-146,148-150 pin
101 pin
100 pin
103 pin
102 pin
2 C(PCA9564) is at High.
SSP1(MAIN)
DM-A circuit board (n8)/DM-B circuit board (n12): IC107
192 pin
193 pin
194 pin
195 pin
105,106,108-113 pin
139,145 pin
22 pin
SSP1(MAIN)
DM-A circuit board (n8)/DM-B circuit board (n12): IC107
105,106,108-113 pin
139,140 pin
CPLD
DM-A circuit board (n8)/DM-B circuit board (n12): IC111
56 pin
51 pin
52 pin
32 pin
58 pin
57 pin
SRAM
DM-A circuit board (n8)/DM-B circuit board (n12): IC109
6 pin
7-10,13-16,29-32,35-38 pin
1-5,18-27,42-44 pin
17 pin
41 pin
39 pin
40 pin
CPLD
DM-A circuit board (n8)/DM-B circuit board (n12): IC111
25 pin
24 pin
23 pin
22 pin
40,42-48 pin
39,49 pin
16 pin
I 2 C
DM-A circuit board (n8)/DM-B circuit board (n12): IC115
1-8 pin
14,15 pin
2
I C
DM-A circuit board (n8)/DM-B circuit board (n12): IC115
13 pin
11 pin
12 pin
16 pin
19 pin
18 pin
2 C are
2 C are