An exhibitor demonstrates a flash memory system developed by Huawei at the China International Big Data Industry Expo 2019 in Guiyang, Southwest China's Guizhou Province, May 26, 2019. File Photo: Xinhua

Taiwan Semiconductor Manufacturing (TSMC), the world's biggest contract chipmaker, has opened its Q4 advanced process capacity originally booked by HiSilicon, a chip subsidiary of Huawei to customers, such as Apple, Qualcomm, MediaTek, and AMD, amid a US ban, according to media reports.

The move may increase uncertainties for the Chinese tech giant, especially the rollout of its high-end product series, though it has a stockpile for a certain amount of chips for "emergency use," analysts said.

The iPhone 12 chips have already been in production at TSMC. The A14 processor it ordered will consume TSMC's 5 nanometers production capacity at about 120,000 to 130,000 for Q4, and it expects to "eat" the original 5 nanometers reserved by Huawei HiSilicon. 

In addition, OPPO, Vivo, and other mobile phone manufacturers will increase their orders, reports said.

The Trump administration in May moved to block global chip supplies to blacklisted telecom equipment giant Huawei. The regulation, which began on May 14, with a 120-day grace period, will also affect TSMC, a vital Huawei supplier.

"The firm may have not yet secured a license from the US and is making preparations for the loss of orders from Huawei," Xiang Ligang, an industry analyst, told the Global Times on Monday.

Another insider told the Global Times that Huawei had stockpiled chips which could be enough through a certain period, but "everyone is taking one step and looking around before making another."

The company's stockpiles of certain self-designed chips essential to telecom equipment will run out in 2021, according to a Bloomberg report, citing people familiar with the matter.

"The policy is changing every day," the insider said.

"We cannot just rely on a single company like Huawei but should unite the country's efforts to win this 'battle'," said the insider.

Huawei said in an earlier statement the US ban would impact expansion, maintenance, and continuous operations for networks worth hundreds of billions of dollars they have rolled out in more than 170 countries.

TSMC did not respond to an interview request from the Global Times as of press time on Monday.