Yamaha n8, Service Manual

Page: 126 / 245

n8/n12
126
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.
SSP1(MAIN)
DM-A circuit board (n8)/DM-B circuit board (n12): IC107
SRAM
DM-A circuit board (n8)/DM-B circuit board (n12): IC109
/CS 152 pin 6 pin
Data bus
MMD[0:15]
105,106,108-113,115-118,120-122,124 pin 7-10,13-16,29-32,35-38 pin
Address bus
MMA[1:20]
125-128,132-137,139-141,143-146,148-150 pin 1-5,18-27,42-44 pin
/MWR 101 pin 17 pin
/MRD 100 pin 41 pin
/LBN 103 pin 39 pin
/UBN 102 pin 40 pin
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
2
C(PCA9564) is at High.
CPLD
DM-A circuit board (n8)/DM-B circuit board (n12): IC111-38 pin
I 2 C
DM-A circuit board (n8)/DM-B circuit board (n12): IC115-17 pin
Check that the signal level of the E-/IC(E-PNS2a) is at High.
CPLD
DM-A circuit board (n8)/DM-B circuit board (n12): IC111-59 pin (3.3 V typ.)
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.
SSP1(MAIN)
DM-A circuit board (n8)/DM-B circuit board (n12): IC107
CPLD
DM-A circuit board (n8)/DM-B circuit board (n12): IC111
/CS60RD 192 pin 25 pin
/CS61WR 193 pin 24 pin
/CS62WR 194 pin 23 pin
/CS63WR 195 pin 22 pin
Data bus
MMD[0:7]
105,106,108-113 pin 40,42-48 pin
Address bus
MMA[1],[19]
139,145 pin 39,49 pin
MIRQ 22 pin 16 pin
Check that levels at each control line (data bus, address bus) between the SSP1 (MAIN) and the I
2
C are
moving.
SSP1(MAIN)
DM-A circuit board (n8)/DM-B circuit board (n12): IC107
I 2 C
DM-A circuit board (n8)/DM-B circuit board (n12): IC115
Data bus
MMD[0:7]
105,106,108-113 pin 1-8 pin
Address bus
MMA[1],[2]
139,140 pin 14,15 pin
Check that levels at each control line (/CE, /RD, /WR, /INT, SDA, SCL) between the CPLD and the I
2
C are
moving.
CPLD
DM-A circuit board (n8)/DM-B circuit board (n12): IC111
I 2 C
DM-A circuit board (n8)/DM-B circuit board (n12): IC115
/CS6 56 pin 13 pin
/CS6WR 51 pin 11 pin
/CS6RD 52 pin 12 pin
IRQ[3] 32 pin 16 pin
SDA 58 pin 19 pin
SCL 57 pin 18 pin