RTL8019AS 16bit mode

Hello,

I have built a device based on Renesas' H8/3068F and RTL8019AS. I have
connected the chips in the following way:
H8/3068F       RTL8019AS       Notes
--------       ---------       -----
A[0-9]         A[0-9]          other Realtek's address lines tied to GND
D[8-15]        SD[0-7]         D8<->SD0, D9<->SD1, etc.
D[0-7]         SD[8-15]
/CS4           AEN
/HWR, /LWR     IOWB            connected through HC08 (AND) gate
/RD            IORB
/WAIT          IOCHRDY         line pulled up through 10k
/IRQ0          INT0
               SLOT16          pulled down though 27k
In this HW configuration 8019AS has been working in 8 bit mode very well
for a few months.

Last week I wanted to test Realtek's 16 bit mode (i.e. word-wide
DMA transfers). The only change I made in the hardware was removing
27k resistor and pulling up SLOT16 pin through 360 ohm - just like in
a 16bit slot of a PC's motherboard. Then I switched MCU data bus into
16bit mode (by apropriate ABWCR register setting) and started playing
with Realtek's registers, especially with the bit WTS of the DCR.
Unfortunately, without success. When I read even address, upper byte
was expected register value and lower byte was 0xff. But when I read
even address, I always got 0xffff. The interesting thing is that 8019
still works well in 8bit mode when SLOT16 is pulled up.

Does anyone know how to force 8019AS to work in 16bit mode? I am
looking for any hints, source code, schematics, etc. Any help will be
appreciated.

Regards,
/J.D.
-- 
Jan Dubiec, [EMAIL PROTECTED], mobile: +48 602 101787

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